Guidelines For Preserving Your Photographic Heritage
by Ralph G. McKnight

1. How long would you like your photographic heritage to last?

2. Plan Before You Act

3. The Chemistry of Photographs

4. The Aging Process

5. A Brief Overview of The Media Used in Photography

6. An Attempt to Prioritize Preservation

7. Good For One Generation (20-25 years)

8. Good For A Life-Time (70-100 years)

9. Good For 150 Years or Longer

10. Could Digital Photographs Last For a Thousand Years?

11. Cleaning and Stabilizing Your Photographs

12. Now Its Time To Go To Work

13. REFERENCES AND RESOURCES

14. Emergency Instructions For Water Damaged Photographs

15. Recipe for Gelatin Glue

16. Is Your Paper Acid-Free, Lignin-Free, pH-buffered, Non-buffered, Alkaline, Archival Quality?

17. Bibliography and Resources

18. Addresses

HOW LONG WOULD YOU LIKE YOUR PHOTOGRAPHIC HERITAGE TO LAST? ..........back to top

Through modern computer technology your album full of family photographic treasures could be preserved for descendants to enjoy a thousand years from now. With proper care and storage your original black and white prints could last 150 years and the negatives perhaps longer.

Through skillful use of copying techniques, high quality, low-cost copy negatives can be made for printing as well as for computer scanning. Preserving your photographs requires knowledge together with a bit of patience and hard work, but the results are well worth the effort.

PLAN BEFORE YOU ACT ..........back to top

In some ways learning about photographic preservation can be a bit frustrating. It can also actually be harmful rather than helpful to your photographs. After a little study a person commonly becomes horrified at all the things they have been doing wrong. Sometimes, they will over-react and quickly go do something harmful, such as handle all their negatives to look for damage!

Remember, it's almost never too late to begin preserving your old photos. Please decide right now that you won't do anything to your photographs until you have thoroughly read these guidelines and decide on a preservation plan. If you don't understand, ask before you experiment.

Unless your photographs were just in a flood or fire, you have a few weeks and months to carefully produce your own personally-tailored plan for photographic preservation. This plan should be personal enough to adapt to your own needs, including time and budget limitations. If you get frustrated at how slowly your plan progresses, keep in mind that you did not build up your photographic treasures all at once, and you may not be able to take all the preservation steps at once either.

THE CHEMISTRY OF PHOTOGRAPHS ..........back to top

Photographic preservation is even more complex than most document or painting preservation. To understand why this is so, we must look briefly at the chemistry of photography.

The beautiful old black and white print of your grandparents on their wedding day is really a complex blend of tiny silver particles embedded in the gelatin surface of photographic paper. Chemicals left over from developing the print, dyes, ink, mounting papers, and adhesives round out the conglomeration. Each of these items affects the life of the print in some way.

The gelatin is vulnerable to heat, light, cracking, scratching, fingerprints, bug infestation, mold, mildew, humidity, water damage, etc. The same chemicals which made the print possible are usually left in small amounts in the paper. These will often work against the print over time, causing it to fade or spot.

Many mounting boards and even some photographic papers are acidic. The residual acid left in the paper will break down the paper and eventually ruin the photograph.

Dyes and inks usually fade with time. Some contain chemicals that will accelerate photographic deterioration. All or nearly all common glues and adhesives cause long term damage to photographs (perhaps without even touching the print itself)--some commonly used ones can visibly damage a photograph within five or ten years!

Because they produce better copies and are less chemically complex, photographic negatives and transparencies are often better to store long-term than prints. Negatives too have a silver-impregnated gelatin layer, but the modern ones use a thin, long-life plastic backing that does not easily retain chemical impurities. Partly because of the gelatin, negatives are still subject to heat, light, cracking, scratching, fingerprints, bug infestation, mold, mildew, humidity, water damage, as well as the chemical and physical problems introduced with storage. Even so, this is a shorter list of problems than for prints.

THE AGING PROCESS ..........back to top

One way to think of photographic preservation is to think of every picture as an "aging organism" with so many years of life bundled into it. This aging process can be greatly accelerated or reduced depending on what we do about it. Photographic aging is often a very slow process, and even at the "half-life," most pictures still look quite pleasing and show few outward signs of deterioration.

Since photographs are really a blend of many different parts, the life of the whole is only as good as the life of its weakest part. An example of this is found in the photographic dyes used in color negatives. All the other parts of the negative could endure easily for a hundred years, but the dyes often change color noticeably within ten years.

A BRIEF OVERVIEW OF THE MEDIA USED IN PHOTOGRAPHY ..........back to top

As we welcome in the twenty-first century, digital photography is poised ready to take over as the photographic media of choice. Digital cameras have passed the mega-pixel (a million dots) for $500 barrier. To the consumer this means medium resolution digital cameras are now affordable.

Digital imaging is already the long-term photographic preservation method of choice. High resolution scanners can convert traditional color or black and white photographs into high quality digital images. CD (Compact disk) and its heir-apparent DVD (digital video disk) can provide robust storage media for these digital images. Not all CD writing schemes are created equal, but some experts feel that properly stored and cared for compact disks could last up to 100 years. But the real secret to its longevity lies in the fact that a digital image can be copied with the copy containing the exact same electronic code as the original. Each successive generation of copies is exactly the same, making this photographic concept an archivist's dream! By putting time and resources into preserving high-quality digital images, with backup copies stored separately, you could watch your precious originals deteriorate with time and feel secure that the images will live on.

Aside from digital, the next best photographic media to preserve is typically an original transparency (color or black and white). Generally, a properly-preserved slide or negative will outlast the print made from it and will produce a much better copy print than will a print. This is because when light is transmitted through an image, it carries many times more color and shade intensities than when light is reflected from an image.

When copying or scanning photographs, look for an original negative or slide first. Remember too that photographs produced by professionals are usually copyrighted property (look for the photographer's logo), and are thus subject to copyright laws.

The chemistry and physics of silver with black and white images has been perfected to such a level as to make this media potentially good for 150 years of preservation. If you are really intent on maximizing the life of your black and white negatives, you may need to be selective about who does the developing or do the final archival rinse yourself. Such a rinse can sometimes even be done years later, but you must be very careful in doing it to avoid introducing further abrasion from dust or washing away partially detached silver/gelatin. For more specifics, please refer to the section below entitled: "Cleaning and Stabilizing Your Photographs."

Color photographs are wonderful to look at today, but without digitizing, it is hard to preserve their beautiful bright color for much longer than a generation. It is important to remember that color films have undergone much more experimentation and change in the last 40 years than have black and white. Many methods have been tried in an effort to improve both image appearance and longevity, with today's products being far superior to many early ones. Since "pleasing appearance today" is what typically drives photo product sales, longevity has taken a back-seat in some cases.

One notable exception is Kodachrome © color slide (and movie) film, a product marketed now for over fifty years. This product is capable of retaining bright color images with little noticeable fading for about fifty years. Some other color slide, negative, and print products and techniques can now rival Kodachrome in longevity.

With some of these color products, the dyes fade relatively quickly, but they may still be capable of yielding recognizable images for many additional years. Emerging computerized restoration techniques often are capable of converting a fading image back to its original bright color.

Just a few years ago, the most general path to color permanence for special color negatives and transparencies was to have color separation negatives made. This permits the color to be preserved for as long as black and white media will last (about a hundred and fifty years). Such an alternative is more costly than conversion to digital media and in time may be entirely replaced by the newer technology.

Video images, such as those produced with the popular home camcorders, are an excellent way of capturing the sounds and images of day-to-day life and special events, too. If well preserved and rarely used, expect these images to last as long as with any magnetic tape media--perhaps a few generations. Video signals copy quite well, but unlike digital signals there is signal degradation with each copy generation. In recent years new technology has emerged that is bringing down cost limitations for high-quality digital movies. Copying old video movies to digital media could render these images subject to no further degradation in time.

AN ATTEMPT TO PRIORITIZE PRESERVATION ..........back to top

As we begin our review of basic photographic storage methods the typical reader reaction might be: "Oh no, what have I done to my photographs?" This information can be somewhat overwhelming; therefore, an honest attempt has been made here to present photographic preservation guidelines in an increasing order of importance. Bear in mind that other presenters would change the order of importance on some of these items. Prioritization will help you, the reader, to sift through the many "do's and don'ts" you might learn and focus on the most important things first to protect your entire collection of photographs (those listed in " Good For One Generation" below).

While implementing this basic list, you could take inventory of your collection. You could weigh your time and financial resources and decide which photos you want to preserve to the next level (see "Good For a Life-Time," below). Include in your plan which photos might even justify the time and expense of preserving for longer (see "Good For 150 Years or Longer" and "Could Digital Photographs Last For a Thousand Years?"). As a separate issue, you should also decide what steps to take now to change the way you will acquire and store photographic materials as they are currently being accumulated.

The prioritization offered here is strictly relative to photographic longevity and has little to do with potential costs and time. As you read through the later sections, you will see some things that would be easy to implement now, even though they are not on the critical list. The average person must choose to preserve photographs quite differently than the William Randolph Hearsts of the world would do it! Every effort has been made to show cost-saving approaches to high-quality preservation as well as areas that invite a "do-it-yourself" approach. So hang on, read all of these guidelines, outline a plan of action, then begin to carry it out. Keep in mind that each time you handle your photographic materials the potential is there for new damage to be introduced.

GOOD FOR ONE GENERATION (20-25 YEARS) ..........back to top

The guidelines given in this section are the "critical or basic" list. They will help you "buy time" and add years of life to your photographs. Your personal plan of action must at least address all of these issues.

Could the number one problem on the list be: improper and incomplete photo identification? If it's not the number one problem, it ranks right up there with "rubber cement" and "magnetic pages!" Please remember to always identify the names, dates, and important details of a photograph. Store the basic information with the photo itself. Sometimes, when more detail is needed, such as for large-group photos, it helps to make a photocopy of the photo and store it in another place with all the details written on it. Ordinary pencils (always #2 or softer), carbon-ribboned typewriters (please, no direct impact), pens with carbon ink, and India ink have been found to be safe and effective for photograph identification. Avoid using oily or odorous erasers. Nearly all other kinds of pens, pencils, and marking equipment will eventually damage your photographs; acidic products are especially damaging. Writing on the back of a print can usually be done safely, but watch out for pressure damaging the emulsion. Please don't write on the front of a photograph--special touch-up pencils and paints are the exception.

Rubber cement and similar adhesives are surprisingly deadly when used on or even near photographs. The acid in them causes rapid aging and cracking of the emulsion and paper backing. The organic compounds in them cause the image to fade, and the sulfur they contain reacts with the silver.

Avoid the photo albums with self-adhesive boards behind clear plastic (Mylar) covers. These are sometimes called "magnetic" pages. The adhesive in most of these products contains PVC and other plasticizers that emit harmful fumes. Do not use cellophane or other common pressure-sensitive tapes directly on the photograph or negative, as nearly all varieties contain acidic adhesives.

There are adhesive products found in most art stores that are non-acidic, such as rice hinges and safe plastic or paper tapes. 3M double-faced acrylic tape No. 815 is generally considered safe with photographs. Where possible, it is always best not to use tape directly on the photo itself. Use it for sealing storage containers, etc. So many products have been found to be damaging in the long run that it is best to be suspicious of all glues and adhesives and anything else that gives off any kind of odor.

There are a few glue products considered safe. The only glue that the author has had enough experience with to recommend must be made from gelatin (see "Recipe for Gelatin Glue," found below under REFERENCES AND RESOURCES).

You will soon discover that not all plastic materials are "photo-friendly"; in fact, most are harmful. There are safe plastic storage sleeves and unsafe ones. Never store photographs, slides, or negatives in the very popular vinyl pages or vinyl sleeves. Vinyl products contain plasticizers (liquid or oily plastic) which will soon cause color dyes or black and white images to fade. Other similar products also contain plasticizers. You can often detect them by an almost "oily" appearance or an odor (the new car smell), or they have a tendency to cling to each other.

You can't always tell if a plastic is safe by its chemical name. For example, the grade of polyethylene used to make throw-away sandwich bags is not produced to the same specifications as polyethylene archival storage sleeves. Our city landfill engineers are requesting that plastics designed for day-to-day disposable use be formulated to readily break down into environmentally safe by-products. Plastics that soon disintegrate are great for landfills but not for storing your photographs in.

In recent years plastic product labelling has greatly improved. If the product doesn't say: "for archival storage," don't risk using it for your photographs. Local photo and art supply centers sell these products as do many nation-wide distributors (see partial listing below under "Addresses").

At some time most of us have used dangerous products in storing photographs. By carefully reviewing the section below named "Cleaning and Stabilizing Your Photographs," you will learn ways of trying to stop the progress of photo deterioration.

Where do you store your most precious photographs? How would you feel about inviting your photographs into the same clean, dust-free living conditions that you enjoy so much? Bring them into your study, your office, your bedroom, your living room, your winter-heated and summer-cooled space. Be sure the temperature and humidity are low. Be sure they are away from any smells, dampness, plumbing, heat, direct sunlight. If you don't want them near you because they smell or are dirty, there is something drastically wrong with how you are caring for them. Never store photographs in a damp basement or near the floor (especially cement floors).

Remember that photographic materials are easily scratched, especially the emulsion side of the print or negative. Don't rub them with anything (except as instructed below in the section: "Cleaning and Stabilizing Your Photographs"). Don't store them in such a way that abrasive dust can be imbedded in them. Keep them clean, especially when viewing them. Try to keep food and fingerprints away from them.

Even at this most basic storage level, do make up your mind that you will no longer store your photographs in cardboard boxes or wooden cabinets. Please transfer them permanently to baked enamel metal file cabinets or any of the increasing variety of safe, acid-free, archival storage containers available. While making the transfer try to remove any of the obviously harmful items from your new storage box. Remove all paper clips, staples, pins, adhesives, and anything with an odor. Carefully hunt for original newspaper clippings and store them away from your photograph cabinets or boxes. Also, remove all rubber bands and manilla envelopes. Read the following sections before you begin, as you may want to remove additional harmful items while you are at it.

Unless they are hardly ever viewed, filmed home movies will not survive much more than a generation without significant scratches. To help reduce this normal damage caused by the viewing process, copy your original film movies to video and let these stand in for the originals to bear the brunt of the frequent wear and tear.

In fact, copying original videos for day-to-day VCR use is a good way to preserve original videos, too. They should be stored on edge away from electric motors and other magnetic radiation sources. They may be more vulnerable to ultraviolet light damage than other photographic media, otherwise most of the same preservation suggestions apply to video as film.

The final issue you need to prepare for in this section is for natural disasters and theft. Fireproof storage vaults can secure your photographs against both fire and theft, but they are expensive and may not totally protect emulsions anyway. For some of these situations, about the only insurance is to store high-quality copies of your photographs in more than one place. Please don't ever throw your negatives away, but do store them separately. A safe deposit box is one good storage choice. It doesn't have to cost much to save negatives, and they have so many uses to the preservationist. A good way of copying your photographs is to make duplicate prints to share with extended family and friends. Grandma can't ever seem to get too many photographs of your family, and she will usually save them forever. You can even send them to her already placed in archive-quality viewing sleeves.

Much of the damage from fire is really water related. When fire or flood strikes, it is usually accompanied with shock to you; thus your photographs may not be the first thing on your mind. Do you have an "in case of emergency..." list or plan somewhere that would remind you of your photographs? The importance of this lies in the fact that with water damage, time is the major factor. Even a one-day delay in action can greatly increase the damage to your collection. Therefore, as soon as you can get to your photographs, follow the instructions found below under: "Emergency Instructions For Water-Damaged Photographs."

This concludes the section on preserving photographic materials for one generation. By way of summary the basic "do's and don'ts" are:

* Develop the habit of fully identifying and labelling all photos. Use soft pencils and special ink.
* Separate the photographs containing rubber cement, magnetic pages, or other damaging adhesives or tapes from your main group of photos. Clean them according to instructions in "Cleaning and Stabilizing Your Photographs," below. Avoid using these items in the future.
* Learn to detect and avoid plasticizers.
* For photos use only those plastic products that say they are of archival quality.
* Store your photographs in a dust-free, low-temperature, low-humidity environment, and keep them clean.
* Permanently transfer your photographs from their cardboard boxes to acid-free storage containers and work toward eliminating photographically harmful substances from those new storage containers.
* Copy home movie film and original videos to videotapes, and use these copies to absorb most of the viewing wear and tear.
* As insurance against loss, store your negatives separately from your prints and send lots of special photographs to friends and family.
* Include the "Emergency Instructions For Water-Damaged Photographs" in your emergency plans.

GOOD FOR A LIFE-TIME (70-100 YEARS) ..........back to top

Before really focusing on the following list of items, be sure you understand and are implementing the previous, more critical list of guidelines. By carefully following all the instructions in the above section, you should be able to avoid the most devastating photographic storage problems that arise. The tips in this section are more specific and detailed, but when followed they could increase the life of your photographic media by three or four times.

Always handle photographic materials by the edges only, and then touch them as little as possible. Fingerprints contain acids and oils that will eventually begin to appear as stains on prints and negatives, which will always remain on them. Cotton gloves are always recommended when handling photographs. Chemical cleanliness includes remembering that rubber bands and even some paper products contain sulfur, which like rubber cement will break down the silver image in photographic materials. The harmful product list includes wood finishes, household cleaners, and the like.

To preserve photographs for a lifetime, "tighten up" your efforts against acidic and odorous products and materials. Make sure that all papers, boards, wrapping, etc. are acid-free (or pH buffered). To better understand this terminology, please study the section entitled: "Is Your Paper Acid-Free, Lignin-Free, pH-buffered, Non-buffered, Alkaline, Archival Quality?" If there are questions, test products yourself with a pH-testing pen. Do not store photos in cedar chests or anything giving off an odor. In fact, avoid all wooden containers (even albums with wood), as well as leather products and most cloth. Keep photos, negatives, etc. away from direct sunlight and ultraviolet radiation sources (such as fluorescent lights). You should store your photos away from photocopiers and laser printers that emit ozone, which is harmful to photographs.

For video (camcorder type) images, always purchase the highest quality videotapes. Store them fully rewound, on their edge in a cool, dry place. Neither video images nor film movies will survive much beyond this length of time without copying. Rather than depending on home video movies alone, have some of your favorite movie clips digitized and stored on CD or DVD.

Remember to never throw away negatives. Storage of negatives and slides is best accomplished in sleeves or envelopes made of archival triacetate or polyethylene. Polyester (Mylar D) is chemically safe, but the sharp edges could scratch negatives. Some of these products are heat-sealed and contain no adhesives. They are transparent so the negatives are easily viewed through them, and they cost just a few cents per negative. Most photo products do attract dust and insects, so be sure the storage container can be sealed.

Remember to only store one negative (or strip of negatives) in each sleeve or envelope. If the negative strips come back from photo processing containing a strip of paper or plastic taped to them, remove the tape immediately and place the negatives in individual protective sleeves. Never store prints (such as those made for identification purposes) with the negatives themselves. There is more chance for harmful processing chemicals being left in the print than in the negative, and thus the negatives could be contaminated by the prints.

Prints are made for viewing, yet they are ideally stored in the dark. If good quality original negatives exist, you can focus your preservation efforts on ideal negative storage. View the prints as you like, and replace them when they get worn. Prints can also be stored in the above-mentioned plastic sleeves or pages. This is usually a good compromise between maximizing safe storage conditions, yet still keeping the prints in an attractive display for viewing purposes. If albums are used, be sure to get only those pages, mounting devices, etc. that are totally acid free. Protect photos from face-to-face contact. Do not overlap photos on album pages.

Particular attention should be made to cleaning soiled and damaged photographs. Please refer to the section below entitled: "Cleaning and Stabilizing Your Photographs." If they are at all brittle, the prints should have a heavy piece of acid-free board behind them to prevent them from cracking. In fact, an acid-free mat board can be cut into a frontal piece, framing the print. This front mat can be heat-sealed to the back board on two or three sides, after which the print is then slipped inside this reinforcing sandwich. This type of envelope keeps the print from slipping around, and when it is then placed inside a polyethylene sleeve (or behind a glass frame, etc.), the print is also protected from dust.

It is preferred not to mount photographs to mounting boards in a permanent way. To do so adds a new dimension to potential problems, namely any chemicals introduced by the adhesive and board. If dry-mounting tissue is used to mount a photographic print to an acid-free mounting board, be sure to use low-temperature mounting tissues so as not to damage the emulsion during application.

There are a few commercially available adhesives that are considered safe to use with photographs. In preference to using adhesives in mounting, use archival plastic sleeves or mount photographs on acid-free paper by cutting small slits for the corners of the photos to be tucked into. Be careful not to damage the corners of photographs by tucking them in.

When framing a photo, there must always be a sealed air space between the photograph and the glass, otherwise the normal swelling of the gelatin layer will etch it to the glass. Be sure that frames used are made of aluminum, stainless, or archival plastics. These products are becoming more common. A desiccant (such as silica-gel) can be used to bring the humidity of a print down prior to framing it. It is not recommended to use desiccants for archival storage as they can actually increase dust.

Techniques for increasing the life of exposed color films include placing negatives and slides in properly sealed cold storage, such as an ordinary freezer. This technique also extends the life of the old nitrate-based films. Some slides stored in glass mounts and some specialized color prints such as Ilfochrome Classic© (formerly Cibachrome) might survive a life-time without fading, but these are the exceptions.

Preserving for a life-time or longer with no major color shifts is unattainable for most of today's color media without making extensive use of copying. There are many high-quality copying techniques available today. Most of these are still quite costly and some do not focus on archival preservation methods. Try to find a service that will copy your most original media (preferably a negative or slide) to high-quality digital media or at least to a negative or slide. Doing so will minimize degradation of image quality through multiple generation copying. Having color separation negatives made will retain the color code for as long as black and white negatives last. Ask your professional service about copying to restore the shifts in color balance caused by aging. Also remember to honor the laws that apply to copyrighted photographs (look for the photographer's logo on the face of the print).

At the life-time preservation level, more extensive use of copies is also made for viewing purposes so that the original media may be preserved in more permanent storage. Special color photographs are also often copied to black and white to help maximize the life of historic images.

Preserving photographic materials for a life-time requires a bit more care and knowledge than the first level. By way of summary the basic "do's and don'ts" are:

* Handle all photographs with cotton gloves. Learn to avoid harmful chemicals in photographic storage.
* Tighten up your efforts against acidic and odorous products and materials.
* Shoot a roll of 8mm Kodachrome movie film once in a while, copy it to video, then use the video version for viewing while storing away the original.
* Storage of negatives and slides is best accomplished in archival-quality sleeves or envelopes.
* Storing prints in archival plastic pages helps protect them and allows for viewing. This is a good storage compromise.
* Special acid-free reinforcement boards can protect fragile or brittle photographs from further damage.
* It is preferred not to mount photographs to mounting boards in a permanent way.
* When framing a photograph, keep a sealed air space between the photograph and the glass.
* Work within copyright laws to make high-quality copies of all important color photographs. Also copy some color media to black and white.

GOOD FOR 150 YEARS OR LONGER ..........back to top

In this section we are focusing strictly on long-term photographic preservation techniques with no compromises. At this level it must be pointed out that there are many products advertised in photo magazines or sold at your local photo supply house which will definitely damage photographic materials over time. Be careful who you get advice from, since most people are actually not aware of the unique problems associated with long-term photographic preservation.

This "150 Years or Longer" heading was not just arbitrarily chosen. This is considered to be the life expectancy for the highest-quality black and white photographic media, although some negatives may go even longer. The science of photography hasn't been around much longer than 150 years, so it is hard to tell how well photographs will age with time. Atmospheric conditions are changing, too, and the air we breath may not be as "photo friendly" as it used to be.

Please remember that this presentation is a progressive one. It is important that you understand all of the items in the two previous sections--Good For One Generation (20-25 years), and Good For A Life-Time (70-100 years)--and then add the following list to them.

In order to maximize photographic preservation to the limits that time will give, there are storage and other cost factors that may be prohibitive to the average private collection. Don't let this discourage you--read on! Many of these tips are also within the budget of nearly anyone, and some will add decades to the life of your photographs.

Two of the most critical factors in how long a photograph will survive are: what quality of processing or photo-finishing did it originally receive, and how long was it neglected before being brought into archival storage conditions? Proper decisions made at the beginning of the "photographic life" result in decades of extended life expectancy.

Be very "picky" about photo-processing, finishing, and copying services. Select only original processing of the highest quality, and do not send negatives to processing laboratories that would scratch, soil, or put adhesive tape on them. Most contaminants which shorten print life are introduced through sloppy handling in the processing laboratory. To avoid this problem, specifically request archival-quality photo processing of your local photo dealer. Also, ask about archival toning techniques.

As a cost-saving alternative to outside archival services, you can rewash your own negatives and prints when you get them back from original processing. If you choose this approach, remember to request that your negatives not be cut into strips when developed. Rewashing introduces new handling risks and must be done properly, but washing them yourself (especially the negatives) is a good way of insuring that it is done to your desired standards.

After negatives return from outside facilities for processing, copying, reprinting, etc., always inspect them for new contamination. Blow them with "canned air" to remove dust, and rewash them, if necessary, prior to returning them to their archival storage sleeves. Refer to the section below entitled: "Cleaning and Stabilizing Your Photographs" for more details.

The subject of rewashing film leads into the problem area of fixer stains. Fixer, a chemical used in photo processing is supposed to be thoroughly washed away but often remains in small quantities in prints. It also naturally becomes part of the airborne dust in all photo-processing facilities. When fixer dust lands on negatives or prints, it leaves a little spot which can even expand over the years. Other chemicals used in photo processing will also damage your photographs over time. Most large photo-processing facilities have special air-filtering systems to remove this kind of dust. Cleanliness and good handling techniques minimize but do not eliminate this problem. Rewashing your film when it returns to your collection can give you the peace of mind that no new chemicals have been introduced.

If you decide that extending the life of your photographic media to its ultimate length is important to you, then you should establish a policy right from the start that no photo development (wet chemistry) will be done in the same building as you select for the archival storage of your photographic media. Rewashing your film in the same building may not introduce significant new airborne chemicals, but this should still be done in a separate building if possible. Many hobby photographers like the freedom and enjoyment they get from processing and printing their own films. Though some of the skills learned in doing this are valuable also to the photo archivist, the chemical contamination risks make the two disciplines incompatible unless separate buildings are used and great care is taken to avoid transferring chemicals (even on hands and clothing) from the laboratory to the permanent storage facility.

The ideal archival storage facility would be extremely clean and dry, with dust, humidity, and air temperature controls. The floor would not be of cement. The floor, walls, and ceiling would be well sealed, easily cleaned, and free from chemical smells, exposed wood, acidic products, and plasticizers. The lighting would be incandescent, the windows not too large and shielded from direct sun-rays. Food and liquids would not be allowed in the storage facility. This would not only reduce the risk of direct damage but also secondary damage from attracting insects or rodents, which could also be attracted to gelatin. Use of cotton (or better) gloves would be mandatory in such a facility.

Photographic materials would be screened prior to admittance to this ideal storage facility, and those items not meeting the proper criteria would be stored elsewhere. The photographic storage cabinets would be of baked-enamel-coated steel (or higher quality). Since maximum photo life is the goal, viewing of photographs would get little consideration in our ideal facility. Very good quality copy negatives and prints would be made from all originals in the collection and stored separately. The copy prints would be used for viewing purposes while the originals are properly stored away. Each original would be stored in its own separate sleeve or archival envelope, isolated from dust, etc. (in other words, albums and multiple storage sleeves would not be used).

Such envelopes can be folded so that no adhesives need be used to hold a print in place. An air space in front of the prints allows the emulsion to remain healthy. The most permanent prints should still typically be made using the old non-resin-coated papers since the brightness, tone, and overall chemistry of these papers are least affected with time. But be careful--though they will outlive resin-coated papers, the uncoated papers are much harder to wash properly for long-term storage.

Do these measures seem a bit like putting a "space suit" on each photograph? Perhaps so, but remember that every photographic item in a collection comes with its own unique set of chemical problems. It is important to isolate contaminants and prevent them from spreading to adjoining photographs. It is generally thought best not to totally seal the photographs away from the atmosphere but to allow clean, cool, dry, dust-free air to circulate naturally around the cabinets and storage envelopes.

Glue and adhesives would not typically be used at all in ideal circumstances. Special care would be taken to avoid even acid-free products and glassine sleeves that contain a seam where glue was used. Similarly, pressure-sensitive tapes would not be used at all. Photographs would not be permanently mounted to mounting boards-- not even if the boards are the archival-quality type (please study the section entitled: "Is Your Paper Acid-Free, Lignin-Free, pH-buffered, Non- buffered, Alkaline, Archival Quality?").

Where practical, old photos would have mounting boards carefully removed (don't try this unless you know how). On rare photographs, such as some that are torn or buckled, mounting might seem to be the best storage solution. It is recommended that this be done with a special gelatin glue (see "Recipe for Gelatin Glue" below). By water-soaking a photograph mounted with this glue, it can then be safely removed from its mount.

It is true that some of the ideas presented in this section are rather idealist to the average person, but we can still try to get as close to them as is practical for each situation. Here is a summary for preserving photographs at the "no compromise" storage level:

* Be careful not to use popular products, sold even by photo supply centers, that will damage photographic materials over time.
* Two of the most critical factors in how long a photograph will survive are: what quality of processing or photo-finishing did it originally receive, and how long was it neglected before being brought into archival storage conditions?
* Be very "picky" about selecting only the best photo-processing, finishing, and copying services.
* Becoming proficient at rewashing photographs yourself (especially the negatives) is a good way of insuring that this is done to your desired standards.
* To achieve the ultimate in photographic media storage, do all wet chemistry in a separate building from where your archival photographic media is stored.
* The ideal archival storage facility should maintain strict control of cleanliness, humidity, dust, temperature, building materials, lighting, food, liquids, and cabinetry.
* Emphasis is placed on proper original-print storage, with copies made for viewing.
* Each photographic item in a collection comes with its own unique set of chemical problems. Individual storage envelopes help isolate contaminants and prevent them from spreading to adjoining photographs.
* Glue, adhesives, and permanent-mounting methods are not typically used at all in ideal photographic storage.

COULD DIGITAL PHOTOGRAPHS LAST FOR A THOUSAND YEARS? ..........back to top

The typical photograph of today is simply not prepared to hold up for a thousand years. There are a few ultra long-term schemes for preserving negatives, such as using glass and gold. There is a platinotype print, utilizing platinum and palladium that is said to last up to 500 years. These techniques are hardly practical for most of us. Another approach to extended photographic preservation is a series of systematic copies made over time. This approach can even be coupled with artistic touch-up work to help restore some of the missing highlight and shadow detail to the image. After a few generations of copying, this technique would more closely resemble a painting than a photograph, but it would do the job of preserving the historical moment.

The systematic copying scheme for the twenty-first century with the best hope of retaining its quality for a thousand years is digital imaging. With this technology, copies can be of equal quality to the original--to the original digital image, that is.

Today's digital photograph might be thought of as a file of computer instructions that define a grid of small square units called pixels. Each pixel is of one solid color which can be of any shade under the rainbow but may be limited by the color scheme defining the photograph. Computer software sends the grid of pixels to the monitor for viewing or to the printer for output as translated printer code. If the photograph appears to lack detail when printed or viewed on the computer monitor, then the viewing size is too large for the total number of pixels in the image. With monitors, this problem is remedied by increasing the screen resolution (which makes everything smaller). For a printed photograph, packing in more pixels per inch (ppi) also requires that the resolution be increased and the print dimensions become proportionately smaller. For 600 dot per inch (dpi) laser and ink-jet prints, 150 ppi is a medium resolution, but professional lithographers prefer 300 ppi.

Most professionals produce digital photographs designed to fill a specific job. In long-term photographic preservation we usually don't have the luxury of knowing what specific future job a photo will be needed to fill. As a compromise, it is recommended that we store the largest print size that we are likely to need for a given photograph. So, if our largest print size is 8 x 10 inches, and the lithographer wants 300 ppi, we would store 2400 x 3000 pixels. This digital photograph would create an uncompressed file size of over 20MB (megabytes) for full color. This is not an uncommon file size for high resolution digital photography. If your digital camera will not take photographs with this high a resolution, then you must either cut back the size of the largest print wanted or you must use a combination of film plus scanning.

High resolution scanning is an art that many people prefer to leave to the professional service bureaus. A successful large-scale scanning service that many professionals use was established several years back by Eastman Kodak Company and is called "Kodak Photo CD©." This service provides a high quality scan of new or old photo media, a series of saved photo resolutions, a file compression technique that seems to maintain photo quality, and a CD end product designed for long life (not all CDs are). As digital imaging evolves from year to year, many other companies are working on improving the technology, and today new scanning and digital services appear at an almost dizzying rate. It is recommended here that these new imaging and storage techniques be measured for quality against the excellent "Kodak Photo CD©" standard.

Do-it-yourself photograph scanning is also becoming popular. Scanning your own photos may save a little money but is rather time consuming. To effectively work with 20MB and larger file sizes, please be sure your computer hardware is the latest and greatest with not less than 128MB of RAM. That 128 number seems to be the point where disk-caching stops for most photo software--and believe me when that happens your whole attitude will change about working with large photo files!

For scanning photo prints, the scanner type may not be as important as your computer RAM. Most color flatbed scanners of today are capable of scanning 300 dpi in 24 bit color. However, most flat bed scanners are designed to scan high-contrast documents, not photographs. Such a scanner can still be used, but the resulting scan may require tone range adjustments with photo editing software (otherwise all the people in your photo have that "unshaven look").

In an effort to simplify, one could determine a proper scanning resolution based on three things: the maximum resolution rating of your scanner; the size of the print, slide, or negative you are scanning; and the maximum print size you would prefer to make from it. As a general rule, you don't try to make a copy print larger than double the size of a scanned original print. So, if you are scanning a 2 by 3 inch print, you should not expect a copy larger than 4 by 6 to be pleasing to the eye. To produce a 4 by 6 you should scan the 2 by 3 at a resolution of 600 dpi (scanner dots per inch can be thought of as interchangeable with pixels per inch, but printer dots per inch are different). Scanning at 600 dpi will give you the preferred 300 ppi for a 4 by 6 print, but if your scanner can't do 600 dpi, then use the maximum scanner resolution instead.

If we scan a negative or slide instead of a print, we can typically produce a pleasing looking print that is much larger than double the size of its scanned original. We would also reap the benefits of increased tone range that come from working with a transparency. But, unfortunately, increased problems with dust, scratches, and the need for a specialized scanner often become the limiting factor. A 1 by 1.5 inch (35mm) slide should be scanned at 2400 dpi to produce an 8 by 12 inch print. For this job you would pretty much need a special photo scanner, and even if you choose to get one, remember that each particle of dust on that slide will be magnified 8 times also! Maybe the service bureau idea is looking better all the time--at least for negatives and slides. It should be mentioned here that Nikon makes a 35mm film scanner that includes a surface scan and, through software, removes dust from the final digitized image. Great things are happening in digital photography!

Now what about digital image enhancement and restoration? Even if you choose not to make your own photographic scans, most people want to have a computer capable of viewing their stored digital photographs and making minor image corrections. The field of digital image enhancement is exciting. For many people it is becoming a fun new hobby! Please take seriously the recommendation of getting 128 MB of RAM, and don't make judgments about working with large images until you do. A photo archivist needs to remember that today's 20 or even 50 MB photo file may be a small (or medium sized) file 20 years from now.

The first thing you need to know before jumping into photo enhancement is to be sure your original digital files are saved as "read only" files--consult your operating system help files on how to do this. "Read only" makes it impossible to change the original file, thus all changes are saved to a different file name. This allows you to progressively enhance your photo, periodically saving to a new "read only" file that cannot be changed. It also makes it safe to introduce your children to photo enhancement without worrying about their putting beards on all the people in your original photograph!

It doesn't take long in working with photo editing software to discover how easy it would be to alter historical integrity. In an effort to preserve your photographic heritage, be careful not to alter it too much. Cleaning the photos up a bit is just great, but when we begin adding new people to a photograph or even removing natural birth marks, we begin to cross the line from reality to fiction. Decide what your policy on this issue will be and then stick to it very consistently.

The last important point in photo editing could be called "learning to avoid the one-way streets." As used here, "one-way streets" are touch-up techniques that rearrange the pixels of an image in such a way that to follow them with some other technique could lead to serious image degradation. An example of this for most software would be the use of a "sharpen" technique. Most images look better after some sharpening, but sharpening should nearly always be the last thing done to an image.

This problem is of particular importance to the photo archivist who is trying to store a good "generic" image for some unknown future purpose. In their efforts to sell software and to cultivate interest in image enhancement, software vendors don't always make it clear what image "side effects" come with using what tools and techniques. This is one reason why you don't want to throw away your original "read only" photo scan.

The ideal image for the photo archivist to store for long-term preservation would be an enhanced (touched-up) image if he is sure that his enhancement steps did not include pixel changing that leads to image degradation--but this is easier said than done. If you can't be sure, then store the original scan. You could even store some step-by-step directions with the scan on how to enhance the image with certain software. As time goes on, it appears that image enhancement is becoming more automated, and it may well be that within a few years so much more could be done for your original scans with so little effort that you'll be glad you stored them.

Storing digital images for long-term preservation requires some knowledge and planning. The first rule for preserving any computer files is to back them up. If your images include slides, negatives, or prints, these may be considered backups too.

Compact disks are an excellent medium for storing image files. Today, some CDs are writeable, whereas the earliest CDs were always "read only." Some CDs are rated as archival quality and should last 100 years; others develop problems very early, so be careful. Don't ever rely on a single CD--remember the first rule; always have a backup.

DVD is coming of age and may take over as the most logical image storage medium. It has already taken over for digital video. As this or other high-quality technology develops, copying images to it will help preserve the images. Remember, it is maintaining a good copying scheme that makes digital imaging the best hope we currently have for preserving photographs for a thousand years.

The mention of DVD and copying brings up a new challenge. The reason DVD spent so long on the drawing boards was that the movie industry needed a digital format that was robust enough, in terms of security, to protect their copyrighted images from being stolen. With CD images we have been able to say that each generation of copied images is of equal quality with the parent image. But as new, more sophisticated digital technologies arise, we may not always be able to say that. So, there are some new "one-way streets" to watch out for.

Up to this point little has been said about digital compression and file formats. These are among the most rapidly changing issues in digital photography and are somewhat a matter of personal taste. Because of the dramatic increase in large-file handling tools, compression may not be as essential some day as it used to be. If you choose to compress your files, either use one of the no-loss compression schemes or use one specifically designed for image file compression, such as Kodak Photo CD©, or JPEG. Nice features in JPEG include the ability to select your own compression level and the use of the "progressive" feature, which is particularly handy for internet photos.

With file formats, important considerations to the photo archivist are permanence and conversion. Choose popular formats that are easily converted. Consider formats such as Kodak Photo CD©, or FlashPix, where multiple resolution images are stored. When storing a single resolution only, remember that storing too many pixels has its problems but not as many as storing too few. Therefore, store enough pixels to produce the largest printed image you might want made from that image. Today, calculate the total pixels based on 300 pixels per inch. Generally, it is better to store more pixels and do more file compression than to not store enough pixels.

So, digital photography and storage has all the signs of being more than just a fleeting fad or passing idea. It is forever changing the way we think about images, even motion pictures. It is expanding the possibilities of preserving images through perfect copies. It is the best hope we currently have for our photographic heritage lasting a thousand years or longer.

CLEANING AND STABILIZING YOUR PHOTOGRAPHS ..........back to top

Now you are almost ready to begin working with your photographs. Before starting you will need some specific information about cleaning techniques. If you have some neglected or even some badly-damaged photographs, remember it is almost never too late to salvage them. This process must be done one by one, treating each print, negative, or slide according to its own unique needs. It is important to understand that cleaning carries its own risks, and it is hoped that what you do will improve the overall condition of the photograph.

If the photograph is especially important to you, then before beginning the cleaning process make a copy of the original as a backup in case something unexpected happens. Find a photo of lesser importance that appears to have the same problems and work on it first; there is a certain "learning curve" to cleaning photographs.

The first step is to thoroughly examine the photograph--usually under low magnification (be sure you are wearing cotton gloves). Look for evidence of abrasion, cracking, mildew, mold, or insect damage to the emulsion layer. Next look at the substrate--the paper or film that holds the emulsion. Does it look healthy? Is the print paper brittle--is it soft, mushy, or falling apart? If it is a print or slide, is the mounting board of good quality; is it acid-free? What kind of adhesive is present?

Most cleaning and stabilizing is done by blowing, dusting, washing, erasing, scraping, removing mounts and adhesives, mounting, applying adhesive, and pencil touch-up. If the emulsion or substrate is soft, crumbling, or flaking away, then any cleaning at all, even blowing with "canned air," could damage the image in the affected area. About the only thing one might do to slow this deterioration down would be to apply gelatin glue over the damaged area--but in some cases this might accelerate the spreading of deterioration to other areas. If the softening is localized in an area that is not critical to the photograph, it would be best to cut out the bad area. If the softening or rotting has begun on the mounting board only, then it is definitely time to remove the photo from its mount (see instruction below).

Other than for the softening emulsion condition mentioned above, "canned air" blowing is the safest and most widely used photographic cleaning technique. It is good practice to blow off photographic media prior to returning it to its archival storage sleeve. Dusting with a soft brush (camel hair or equivalent photo brush) is the next safest technique. The only situation where brushing would be less safe than blowing is in the case where abrasive dust could be pushed across the face of the photograph, scratching the emulsion. Brushing can be more effective than blowing for stubborn problems (such as a hair).

Scraping with a pen knife is obviously quite risky and requires a very delicate touch. One would not use such a tool to touch an emulsion itself, but under low magnification and with a steady hand, one can cut away the top bulk of some contaminant that may have been dropped on the photograph so that subsequent washing could clean the residue away without increasing the risk of staining the entire photo.

The knife is also useful for cleaning and removing mounts, glue, etc. It is not always easy to decide when to remove a mount from a print and when to leave it alone. If a permanent mount is healthy and appears to be acid-free, leave it. If it is not permanent and the mount shows any sign of aging, uncleanliness, or is not acid-free, then remove it. Situations between these two extremes are judgment calls. Sometimes the determining factor is how difficult and risky it is to get the mount off without bending or stressing the print. Sometimes, just the unhealthy part of the mount can be cut away, with the newly exposed part of the print given new structural protection. When removing the mount, be sure to scrape away all the old glue and adhesive. Sometimes a mount is designed to later be removed from its print through soaking.

Washing is of at least two varieties, and both carry additional risk. Generally, the photo media should be in pretty good physical condition to hold up under full rewashing. One might consider this procedure after photographic media becomes soiled, new contaminants have been introduced, or when bringing photo-finishing up to an archival-quality standard. Remove the mount and, using filtered water, follow the same washing temperatures and techniques recommended by the film or paper manufacturer.

For archival preservation use longer washing, soaking, etc. and use the photographic washing salts recommended by the manufacturer to accelerate complete fixer removal. Hang negatives and slides in a dust-free location to dry. Air dry the prints in a dust-free area on fiberglass screens. To remove the curl from the dry prints, carefully slip them (individually) between 2 pieces of acid-free paper (or other appropriate substance) and flatten them out for a day or two under heavy weight.

The second kind of washing might more appropriately be called "spotting," because it removes localized spots, mold, mildew, or stubborn dust that is stuck to the emulsion. This technique can often be done without removing mounted photographic media. Make a mixture of 50% denatured alcohol, 50% de-ionized water. Using a cotton swab or cotton Q-tip carefully apply the mixed solution to the soiled emulsion area. Be careful not to use pressure--just soak, swab, and lift. If caution is not taken, you can actually watch the image of some deteriorating prints fade away before your eyes using this technique--so don't spot the unhealthy ones, and don't apply pressure! If the foreign matter doesn't lift off at first, be patient and soak it longer. This technique can also leave a ring in the area where spotting was done, which may lead to the necessity of full washing. Even with these risks, many photographs can be significantly improved using this technique.

Attempts at removing dangerous adhesives (such as rubber cement, magnetic page adhesive, cellophane tape, etc.) would depend on the condition of the photograph. If you have an original, uncontaminated negative or slide, make a new print and throw the contaminated one away. You may try scraping away excess adhesive, Q-tip/alcohol washing, then full washing. Such prints will probably still need to be isolated from the main collection on storage, because these washing steps don't completely remove most adhesives.

Usually erasing is needed just for pencil marking on the mounts, but occasionally a pencil mark accidently lands on an emulsion. Let's hope it was made with a very soft pencil and is not accompanied by grooving. Sometimes a soft, white or amber-colored eraser applied with just the right amount of pressure can lift all or some of the carbon away from the print. Don't expect miracles here; a less prominent pencil line is much less distracting than a heavy dark one. If you try to get it all, you may begin to erase the image as well. Don't use the oily type erasers nor the colored ones since removing all of the eraser residue is difficult. The trade-off here is that eraser residue itself could damage your photograph over time--ironically, the pencil mark will out-live the print!

It is hoped that most of your mounting chores will be removing old mounts rather than adding new ones. Sometimes mounting in a non-permanent way can improve the stability of a fragile photograph or unite torn parts. The gelatin glue recommended here is quite safe and is even reversible--that is, the mount can be removed later (see "Recipe for Gelatin Glue," below). Be sure to select the right weight and texture of archival mounting board for the job.

Restoring and touching-up photographs is a sophisticated art, but sometimes, with the right tools, even a novice can improve on a damaged photograph. Check with your local photo supplier for literature and supplies in this area. Be sure to use pencils and markers designed for archival photographic restoration. Consider computer restoration instead, because it can be completely reversible.

Fixer spots and stains look like bleach marks on a print or negative. If discovered on a relatively new photograph, then rewashing will probably stop it from slowly spreading across the photo. If the stain is already spreading like leprosy across a print, it has probably also traveled the full thickness of the print, and some combination of washing and cutting may be necessary. If there is no spot on the print, but the entire image is slowly acquiring a bleached look, then the paper is contaminated with residual fixer from incomplete washing when it was originally processed. If the print can hold up to it, additional washing after the fact can stop the progress of this bleaching.

Last but not least, your freshly-cleaned photographs deserve new storage sleeves. Putting them back in their same old storage envelopes would be like taking a bath and then putting your dirty socks back on!

NOW IT'S TIME TO GO TO WORK ..........back to top

Now that you have patiently read through these instructions, and you understand the specific tips on cleaning, you are ready to get started. First write out your specific plan. What can you begin with that will make the most positive difference in your photographic storage system? Review the tips in the summary of the section: "Good For One Generation (20-25 years)" and be sure to include them in your plan. Review the tips in the summary of the subsequent sections, and decide which of them are realistic for you to include now and which will take future time and money to implement. Set goals and develop a time-line. Which items would you like to learn to do, and which would you prefer sending out to professionals? How can you change storage practices for future photographs you acquire? Don't try to do it all overnight. Be energetic about your planning, and then follow the plan at a pace you can maintain without losing interest. Keep the ultimate goal in mind: your decaying photographic heritage is worth preserving.

REFERENCES AND RESOURCES

        
EMERGENCY INSTRUCTIONS FOR WATER DAMAGED PHOTOGRAPHS ..........back to top

In case of flood or other water damage, the following procedures should be followed immediately after a person can get to the photographs:

* Keep them wet! Letting the photos dry and stick to each other or to their envelopes usually causes irreversible damage.
* Don't let them stay wet so long they begin to disintegrate. Two or three days is about as long as they should stay wet. If they cannot be salvaged, washed, and dried in that length of time, then perhaps one should consider freezing them. However, freezing creates many new risks, such as cracking and emulsion damage from ice crystals.
* Put the wet photos in clean plastic buckets of cold water. Immerse wrappers, envelopes, album pages, and all. Add 1/4 cup of formaldehyde for every gallon of cold water. Try to keep the water temperature at 65 degrees or lower.
* As quickly as time will allow, begin carefully removing the water-soaked prints, negatives, slides, etc. from the cold water, and pull them out of their wrappers. Wash them in running water (65 degrees) for 15 minutes or longer.
* Hang the negatives and slides on a clothesline in a dust-free location to dry.
* Air dry the prints in a dust-free area on fiberglass screens.
* To remove the curl from the dry prints, carefully slip them (individually) between 2 pieces of acid-free paper (or other appropriate substance) and flatten them out for a day or two under heavy weight.

RECIPE FOR GELATIN GLUE ..........back to top

The following recipe was taken from Eastman Kodak pamphlet No. E- 34.

1 tablespoon gelatin (Knox Plain Gelatin or emulsion-quality gelatin).
1/4 teaspoon ammonium hydroxide (concentrated).
1/4 teaspoon Kodak Photo-Flo solution (1:200 dilution). *
1/4 cup warm distilled water (120 degrees F). For thinner mixture use 1/2 cup water.

* Make up a solution of 1 part Kodak Photo-Flo solution to 200 parts distilled water, then use 1/4 teaspoon of this dilution in the recipe as given above.

Dissolve gelatin in warm water, cool, then add ammonium hydroxide and diluted Photo-Flo solution. Strain warm gelatin solution through an absorbent cotton pad or cloth. Keeps for only two or three days at room temperature. Mix fresh or keep in refrigerator. For use, warm the gel solution slightly to liquefy. Apply with new brush or cloth.

This formula is very similar to the chemistry of the gelatin layer in photographic products. Remember to avoid mixing or storing this adhesive using products containing plasticizers, metals, or other substances that might be harmful to photographs. It can be used in many ways, including the following: 1) As an adhesive for mounting prints. The mounts can later be removed by soaking. 2) To adhere fractured gelatin emulsion which has lifted from dry plates. 3) To clean and "heal" abraded gelatin print surfaces.

IS YOUR PAPER ACID-FREE, LIGNIN-FREE, PH-BUFFERED, NON-BUFFERED, ALKALINE, ARCHIVAL QUALITY? ..........back to top

Do you get confused at all these paper-type buzz-words? Perhaps a brief (over-simplified) explanation will be helpful. Wood products, including most paper, contain a natural compound called lignin, which over time produces photographically harmful break-down products of two varieties: acids and odorous substances (phenols). Besides the lignin problem there is an "old" paper-milling process where sulfuric acid is used to manufacture paper, and a "new" process (which is slowly replacing the old) using limestone in paper making. Most newspaper and craft papers are examples of lignin paper made with the acid process. When lignin-containing paper is made with the new process, or when calcium carbonate is added to paper processed the old (acid) way, it is said to be "pH buffered." Extra calcium carbonate is added to these neutralized, buffered papers to account for lignin breakdown to acid that may occur in the future. This pH-buffered paper is usually okay to be associated near photographs intended to be preserved for a lifetime. One exception is that some color dyes contain their own acids or pH-sensitive chemicals which react with the calcium carbonate.

To be even more safe in the long run, look for acid-free, lignin-free, non-buffered paper products. Archival-quality paper or board does not need to be pH buffered, because it is lignin-free and contains no other sources of acid to neutralize. Still, some grades of archival paper are purposely made to be a little on the "alkaline" side of the pH scale to protect them from our human environment, which tends to be somewhat acidic.

BIBLIOGRAPHY AND RESOURCES ..........back to top

The following is a short list of resource material on the subject of photographic storage and preservation; some of which has been very helpful in the preparation of this manuscript.

"Acid-Free Materials Ensure Preservation." Don Norton. Salt Lake City, UT; Deseret News: Church News, March 14, 1992.

Administration of Photographic Collections. Mary Lynn Ritzenthaler, Gerald J. Munoff, and Margery S. Long. Chicago; SAA, 1984. SAA Basic Manual Series.

An Ounce of Preservation, A Guide to the Care of Papers and Photographs. Craig A. Tuttle. Rainbow Books, March 1995.

Care and Identification of 19th Century Photographic Prints. James M. Reilly. Rochester, NY; Eastman Kodak Co., 1986. Kodak Pub. G-2S.

The Care of Photographs. Siegfried Rempel. Lyons & Burford, February 1, 1988.

Collection, Use, and Care of Historical Photographs. Robert A. Weinstein and Larry Booth. Nashville, TN; American Association for State and Local History, 1977.

Collector's Guide to Early Photographs. O. Henry Mace. Wallace-Homestead Book Co, April 1990.

"Conservation of Photographic Print Collections." Alice Swan. Library Trends, v.30. No.2 (Fall 1981), pp. 267-296.

Conservation of Photographs. Rochester, NY; Eastman Kodak Co., 1985. Kodak Pub. F-40.

"Disaster Preparedness and Recovery: Photographic Materials." Klaus B. Hendricks and Brian Lesser. American Archivist, v.46, no.1 (Winter 1983), pp. 52-68.

"Follow Simple 'Do's, Don'ts' to Preserve Heritage." Wilma "Billy" Plunkett. Salt Lake City, UT; Deseret News: Church News, March 14, 1992.

"Gaylord Preservation Pathfinder No. 3: Archival Storage of Photographic Materials." Syracuse, NY; Gaylord Brothers, March 1995.

Imaging Media-Photographic Processed Films, Plates, and Papers-Filing Enclosures and Storage Containers. New York, NY; American National Standards Institute. IT9.2-1988.

IPI Storage Guide for Acetate Film. Image Permanence Institute. June 1993.

The Life of a Photograph. Archival Processing, Matting, Framing, and Storage. Laurence E. Keefe, Jr. and Dennis Inch. Focal Press, April 1990.

The Permanence and Care of Color Photographs; Traditional and Digital Color Prints, Color Negatives, Slides, and Motion Pictures. Henry Wilhelm, Carol Brower. Grinnel, Iowa; Preservation Publishing.

Photograph Preservation and the Research Library. Jennifer Porro, Mountain View, CA; RLG, 1991.

Practice for Storage of Black-and-White Photographic Paper Prints. New York, NY; American National Standards Institute. PH1.48-1982 (R1987).

Processed Safety Film-Storage. New York, NY; American National Standards Institute. IT9.11-1992.

"Record Life's 'Images and Sounds' on Videotape." Rod Gustafson. Salt Lake City, UT; Deseret News: Church News, March 14, 1992.

Safe Handling, Storage, and Destruction of Nitrate-Based Motion Picture Films. Rochester, NY; Eastman Kodak, September 1995. Kodak Pub. H-182.

"Sharp Photos Make the Memory Vivid." J. Malan Heslop. Salt Lake City, UT; Deseret News: Church News, March 14, 1992.

Storage and Care of Kodak Photographic Materials. Rochester, NY; Eastman Kodak. Kodak Pub. E-30.

ADDRESSES ..........back to top

The following is a short list of companies that supply archival photographic storage products:

Archival Image, 1021 NE 16th St., P.O. Box 3776, Ocala, FL 34478, (800) 688-2485.

Calumet Photographic, Inc., 890 Supreme Drive Bensenville, IL 60106, (630) 860-7447, (800) 225-8638.

Conservation Resources International, Inc., 8000-H Forbes Place, Springfield, VA 22151-2204, (800) 634-6932.

Creative Memories, 3001 Clearwater Road, P.O. Box 1839, St. Cloud, MN 56302-1839, (320) 251-7524.

Franklin Distributors Corp., P.O. Box 320 Denville, NJ 07834, (973) 267-2710.

Hollinger Corporation, P.O. Box 8360, Fredericksburg, VA 22404, (800) 634-0491, (540) 898-7300.

Icon Distribution, 3956 Town Center Blvd. Ste. 122, Orlando, FL 32837, (800) 801-2128.

Light Impressions Corp., 280 Commerce Dr., P.O. Box 940, Rochester, NY 14603-0940, 800-828-6216.

Print File, Inc., P.O. Box 607638, Orlando, FL 32860-7638, (407) 886-0008.

University Products Inc., P.O. Box 101, 517 Main St., Holyoke, MA 01041-0101, (800) 628-1912.

Vue-all Inc., Box 1994, Ocala, FL 32670

Copyright Notice This manuscript: "Guidelines For Preserving Your Photographic Heritage," is copyrighted ©1999, by the author, Ralph G. McKnight, P.O. Box 2524, Grass Valley, CA 95945, e-mail:mcknight@nccn.net. All rights reserved. Copying this manuscript for non-commercial use may be done without written consent of the author, provided such copies are made in full, including this copyright notice. No changed or condensed versions of this manuscript are permitted without written consent. NOTICE Ilfochrome Classic is a trademark of Ilford Photo Corporation. Kodak, Kodachrome, Kodak Photo-Flo, and Kodak Photo CD are trademarks of Eastman Kodak Company