Archival techniques – comments on the past

Allan Lamb, author of Framing Photography and a certified picture framer reflects on the importance of proper archival techniques.

Writer / Allan Lamb

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This is a section of a silver gelatin print that shows poor agitation while it was being processed, which affects archival techniques. The print was sold to a collector and the stain probably did not show at that time. However, since the processing was not completely stabilized during the fixing step, the image continued to darken. The age of the print is about 35 years old.

Often we are told that if you do not know history you are likely to repeat the same mistakes. In photography this is also very true. I work in photographic restoration for two museums and have restored images photographically for many years. I have seen many mistakes that are now coming to light several years after the original image was produced and printed. When I receive a photographic image that is stained or the image is of poor quality, three possible problems exist:

1. Poor technical procedures by the photographer or technician,
2. a particular process has not held up over time, or
3. the way it was presented for viewing over the years.

Since this article is being provided to photographers using many different processes I will try to be more general in my comments.

You are probably very aware of the technical requirements of the process you are using. I suggest that if you do not know your chosen alternative photographic process well, you should do some research into the old procedures and study what is now being done by known master of the process. One of the worst and most regrettable sights is a silver halide print that has been improperly agitated during the developing process. This results in stains that are not often noticeable until several years later. Not only does the stain look bad, but to a collector this is a warning to be very careful in collecting that particular photographer’s work. Several classic photographers are now being collected with concern. The value of the collection of work from that photographer will not reach the level of other photographers of the same school or period. The image is great but the life expectancy of the image is unknown. So lab techniques are important, especially if you want your creations to be respected by collectors.

Lab or processing techniques should be respected by the photographer.

Poor techniques such as using old, impure or exhausted chemistry may save some money initially but will come back to haunt you later.

Timing and temperature of the steps in the process are also important. Depending on the process, the use of tap water with all of its impurities, instead of distilled water can also have a serious impact. Contamination of your chemicals by not properly cleaning your hands or equipment will not only shorten the life of the chemicals but impact the life longevity of your prints.

The paper substrate you select for coating or printing your image, can also have considerable impact on the life of the image. Paper that has been sold as acid free is often wood pulp that has been treated with chemicals such as calcium carbonate. The lignin, which eventually breaks down into acid, is still there and once the stabilizer is finally exhausted the paper will turn acidic. This will take time, however it will happen. Looking at old images that have been mounted or printed on cards will show you a great example of this.

The paper used as the substrate for the photograph was probably made of lignin free paper such as a cotton rag or other high quality paper, but the card that the print is mounted on is often a cheap card stock that has not been treated. Usually these cards, cart-de-visites or postcards as great examples, are now becoming so brittle from acid burn that you can break the card instead of bending it. The acid has caused the paper fiber to be broken down and the card becomes brittle. I have seen this on many late 19th Century or early 20th Century work.

Choice of processes can also impact the longevity of the image. Some processes result in very beautiful images but may be very sensitive to light, temperature or oxidation. Some processes such as the platinum print process if processed correctly will last many years and has become know to be a very collectable image. Use of color dyes are often very sensitive to light and fade rapidly. Most color photographic images produced in the 1960’s or earlier are very faded. Often the owner does not realize the color shifts that are taking place in the image because the owners are color correcting the image in their minds. The loss is especially noticeable if the image has been on continuous display during this period. Much of the early photography that has been on display is now damaged or totally lost.

Another example is the early albumen print which if not toned or stored in a dark dry container will show a considerable loss.

Presentation of an alternative photographic print is as important as the actual creation. Too often the photographer just lets the buyers leave without informing them of the proper way to show or store the image. Just visit a local antique dealer or antique show and really look at the framing of the paper art.

Look closely at the edge or bevel of the mat. If the cut bevel is white or an antique white in color, chances are that it is matted with at least an acid-free board. However, this does not mean that the board is suitable for an antique or collectable print. Lignin-free is the best because the acid causing material is not present. So if the bevel is a darker yellow then there probably is damage already taking place in the print. Look at the area of the print that is actually touching or very near the mat. If you see a darkening of the print, this is acid burn.

This type of damage will take place over a period of time but can be stopped if taken to a paper conservator. For photographic images, it is best to find a photographic conservator. The acid actually migrates to contaminate the print from the cut bevel. It is almost like a cloud of acid. Again look closely at the print and check for what is called “foxing”. This is caused by mildew. It starts out looking like little specks of brown stain. It gets worse over time and is very likely to start in higher humidity higher temperature display areas.

Although I have mentioned platinum prints as very stable images, they are great examples of photographic materials that can cause damage. Platinum and platinum toned prints will burn a reverse image into any paper they touch. This damage will result to any print or mat pressed up against them over a period of years.

Choice of framing is also a source of contamination and an archival technique to consider.

1. Wood frames although very beautiful can cause damage. This is especially noticeable when an antique print is taken from an older frame. The edge of the mat, especially if it is white or an antique white will show acid burn from the edge close to the wood frame. Large mats will help isolate the print from the burning but an aluminum frame, or a wood frame that has been sealed, protecting the mat and print from the acid in the wood, is best for very valuable prints.
2. The back board although not seen can cause even more damage. When an antique print is removed from the old mat, if corrugated board was used – and thus improper archival techniques – the acid burn is often so great that the corrugation is easily seen on the back mat or back of the print.
3. Glazing should be UV protective. This does not totally protect the print but it will help. If reduced light conditions are maintained the print will last much longer.
4. Many times I have been asked to remove photographs from glass. They were framed mounted against the glass surface. It is important to use the proper archival technique. The moisture in the frame caused a mildew to grow and act as an adhesive. There are ways to reduce the damage getting the image off of the glass but almost always there is damage.
5. Uneven fading can be caused by laying the mat over the edge of the print instead of leaving the full image for view. Later if the piece is reframed or matted, there may be a loss of image in the area that had been exposed and a ring of increased density where the mat covered the image.

History has a lot to tell us about the photographic image whether it is the alternative or a mainline process. Here are some suggestions for you to consider:

1. Study the history of your process and review what others have written about it. Go down and if possible look at examples in the museum or antique stores. See for yourself how they are holding up over time. I mentioned albumen prints are often faded, but then you have to remember that they are over 100 years old or more.
2. Make sure that you use the best chemicals and purest water. Use a lignin free substrate to coat your emulsion on. Standardize your lab techniques. Make sure you are timing your process. Keep the tools you use clean, including your hands. Insure that your process temperature is correct.
3. Select a process for your archival techniques that will last or at least consider what is the most important to you: the look of the image or the life expectancy. Some emulsions do not last well over 15 years so this will have an impact on your chance to be known over the years. Do your research if you really want your work to be seen in the next century.
4. Inform your customers about the best ways to present your work. Consider lighting, humidity, temperature, and time on display. As I mentioned earlier, prints that have been on display for long periods will probably show damage. Visit the local community museum. Or go to an antique mall and study the pieces they have to offer. Look for damage. Chances are you will see some.
5. Discuss with the customer the need for lignin-free mats, UV protective glazing and aluminum or lined wood frames. A great way is to show them some examples of damaged prints from the past that you have collected.
6. To eliminate uneven fading along the edge of the print, I recommend keeping the mat at least ¼ of an inch away from the image edge. In this case more is better. Later owners will appreciate this effort.
7. And finally, never frame your print against glass. Always use a spacer or mat to keep the glass from touching the image surface.

Allan Lamb has been working in photography since 1960 and is the author of ‘Framing Photography’ which is now in its fourth edition. He is a certified picture framer and has provided several articles and lectures on the special handling requirements of photographs since his retirement from the United States Air Force. He is presently active in digital photography and providing photographic restoration services for two museums.