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Photo preservation guide Part 1: In the darkroom By Kate Contakos To understand preserving gelatin silver prints, one must understand the make-up of these materials. I will briefly explain the physical nature of paper and the chemistry used in creating these prints, and then explain the best practices in creating long-term archival prints. This is the first part of a three part series on preservation, this serving as the introduction to proactively create preservationally sound prints. Part two will focus on handling, exhibition, and environment. Part 3 of the series will explain the invasive conservation treatment of these prints. Paper: Gelatin silver developing out paper has been around since prior to the last century, and has not changed dramatically. The fiber-based paper has a three-layer structure, with the paper being the support, a baryta layer made up of gelatin and barium sulfate to gloss over the paper fibers, and the final layer, which is a silver-halide emulsion. This is the layer where all the magic happens. This paper comes in all sorts of tones ranging from warm to cool, purplish, sepia, and neutral, as well as variations in surfaces and textures. Regardless of these choices, the main thing to remember is that the paper serves as the support for the silver that the image is created on. Resin-coated papers are also an option, but I do not recommend them for use in any sort of archival or long-lasting print. The polyethylene coating on both sides breaks down over time and eventually causes redux spots and other visibly damaging affects. Whereas there have been improvements in RC paper over the years, stick with fiber-based papers for longer lasting prints of high archival quality.

Contakos, Kate - Photo Preservation Guide

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  • Photo preservation guide Part 1: In the darkroom

    By Kate Contakos

    To understand preserving gelatin silver prints, one must understand the make-up of these materials. I will briefly explain the physical nature of paper and the chemistry used in creating these prints, and then explain the best practices in creating long-term archival prints. This is the first part of a three part series on preservation, this serving as the introduction to proactively create preservationally sound prints. Part two will focus on handling, exhibition, and environment. Part 3 of the series will explain the invasive conservation treatment of these prints.

    Paper: Gelatin silver developing out paper has been around since prior to the last century, and has not changed dramatically. The fiber-based paper has a three-layer structure, with the paper being the support, a baryta layer made up of gelatin and barium sulfate to gloss over the paper fibers, and the final layer, which is a silver-halide emulsion. This is the layer where all the magic happens. This paper comes in all sorts of tones ranging from warm to cool, purplish, sepia, and neutral, as well as variations in surfaces and textures. Regardless of these choices, the main thing to remember is that the paper serves as the support for the silver that the image is created on. Resin-coated papers are also an option, but I do not recommend them for use in any sort of archival or long-lasting print. The polyethylene coating on both sides breaks down over time and eventually causes redux spots and other visibly damaging affects. Whereas there have been improvements in RC paper over the years, stick with fiber-based papers for longer lasting prints of high archival quality.

  • Chemistry: Photography is all about silver. However, the very noble silver alone is inactive, as it must form a bond with a halogen to be light sensitive. Silver bonds with either chlorine, bromine, or iodine to become silver halide, which is what creates the image. Curiously, the size of the silver halides determines the color so the different sizes of silver halides matter, a lot. Smaller, finer grains create a warm tone image, whereas a cool toned image has larger grains of silver halides. In early photographic images (think salted paper prints such as albumen and collodions), all have a reddish-brown hue because the silver halides were tiny. Today, of course, myriad choices of chemical combinations exist. This is just one little factor in the big game of photography fun. I continuously experiment with different films and developers, finding the perfect combinations for particular situations. Regardless of the size of the halides or what silver bonds with, for preservation purposes, proper water and fixing is most crucial.

    A print with high silver content in the emulsion

    Water: It may seem a bit jejune, but I think water is not talked about enough in photography. As a film photographer, there are so many choices to make - the type of camera to shoot with, what subject matter to shoot, what film, paper, and chemicals to use - but it can all be ruined if using impure water. Tap water can have all sorts of minerals and old pipes can leak rust; the best chemicals and most skillful methods of processing will not impact the finished product if the water is not pure.

  • Beginning with developing the film to printing the image, distilled water is the best stuff to use. To achieve distilled water, regular untreated water is heated to the point of vaporizing, and since the boiling point of water is so low compared to the minerals it needs to be separated from, the water escapes leaving behind the sediment.

    Use this water...

    ... not just any water you can find

  • So, to avoid deposits of impurities on the negatives and prints over time, all of which will eventually erode and attack what you thought was a well processed, long-lasting negative or print, please consider using distilled water. It will help achieve archival quality negatives and prints, which will outlast you and provide the world something stimulating to look at for decades and perhaps centuries to come.

    Fixing: I dont think fixing twice is so much an opposing argument as much as it is simply disregarded. In the early days of DOPs (developing out papers), sending prints through two fixing solutions was common practice. The fixer washes out all of the non-developed silver halides, but if not done properly, over time, you will be able to watch your prints break down and die before you do. To properly fix and make an archival print, use the first fixer to wash out most of the undeveloped silver halides, agitating continuously, and the second to wash out what remains from the first fix. The reason is that while the first fix washes the print, it also creates contaminants, so a second fixer is needed to get the print squeaky clean. After a printing session, I always notice my first fixer has a darker, dirtier hue, whereas the second fix looks crystal clean. If the print is not fixed twice, the contaminants eventually penetrate the paper fibers and form mega-strong bonds that can never be washed out, and once oxidized will eventually break down the fibers of the print. So, if you want your prints to last longer than you do fix twice, question its longevity and long-term preservation later.

    Fix twice, hypo, and then put into the print washer for an hour

  • Toning: The black and white gelatin silver print, processed properly and stored appropriately, should last a few hundred years. However, many factors affect image permanence and for the most part, one does not make a print to store it away in a cool, dark environment never to be handled or displayed again. So after processing appropriately using distilled water and fixing twice, for another added layer of permanence and increased image stability, toning is a very good last step. A common toner to use that does not alter the image to much discernible degree is selenium. After properly fixing, the print should run through a hypo bath to clear the fixer off, and then a full washing. After washing, tone with a selenium toner that will then convert the silver to silver selenide which is a more stable compound than silver alone, and will be more resistant to atmospheric pollutants and oxidation. If the desired effect is to have no tonal change, the selenium should be diluted mildly and will yield strictly archival results. Ansel Adams was a big proponent of selenium toning and his prints today are a testament to time as they are still in excellent condition and probably will be for hundreds of years to come.

  • Photo Preservation Guide Part 2: Handling, Exhibiting & Storing

    This is the second part of a three part series on preservation; the first served as the introduction to proactively create preservationally sound prints. This part will focus on handling, exhibition, storage, and environment. The final part will explain the invasive conservation treatment of these prints.

    Whereas it is extremely important to process a print archivally, the handling, exhibiting, storing, and environment play an equally important role in its permanence. Below is a number of steps to take to ensure the longevity of a print, whether it's a print you produced yourself, a print purchased for a collection, or even an antique family photo.

    Handling: Hands are dirty. Even after washing them, all sorts of natural oils exist that can cause harm to photographs and negatives alike. To ensure that no potential oil or dirt gets onto the print or negative, always wear gloves when handling these materials. Some manual dexterity is lost when wearing gloves though, so use extra care and caution when handling with gloves. Typically, I use powder-free nitrile gloves when handling negatives [latex gloves are also fine to use, however, many people have allergies to latex and nitrile are latex-free], and white cotton gloves when handling prints. Even when wearing gloves, avoid touching the image of the print and handle the print by its sides and corners.

  • Handle photographic prints with gloves, and never touch the image

    Exhibiting: Whether displaying prints in a private home or exhibiting in a gallery, matting and framing should serve to protect and promote easy handling, as well as present a visually stunning support for the work. There are many ways to mount the photograph: dry mounting to a board, corner tab mounting to a board, window mats, and direct matting to name a few. Whichever method is chosen, the most important advice is to use the best materials possible. For all paper products used, select materials that are acid-free, lignin-free, cotton rag, archival, and/or unbuffered. These terms are used in various ways, so dont feel shy to ask which is the most archivally sound or safe material to use. Another consideration is that the mounting and framing is reversible. The photograph should always be able to be safely removed from its frame and stored appropriately after its display. I have seen some atrocities which probably seemed like an interesting idea at the time, such as gluing a photograph to a piece of wood, but after a few years the thing had nearly decomposed because the adhesive from the glue combined with the chemical decomposition of the wood, combined and formed a deadly attack on the photograph. So before getting too creative, think about longevity and long-term access.

  • Corner-mounted print on a 4-ply archival mount board

    Storing: When preparing for storage, it is important to remember that a photographic print is a whole bunch of chemistry sitting atop paper. Enclosures and sleeves help protect photographs from pollution, accidental damage through inappropriate handling, and random gashes. There are many options to protect prints, the most common is to interleave with paper and stack prints in an archival box, or store prints in sleeves and then place in a box. When interleaving with paper, it is imperative to use acid-free, archival, unbuffered paper. The paper serves as a buffer between the prints so the chemistry does not migrate to the next print, as well, it makes it easier to handle the print by using the paper as a carrier support to lift it in and out of the box. If using plastic sleeves instead of paper dividers, by sure to use archival quality sleeves that do not contain PVC. Polyvinyl chloride, or PVC, is commonly used but its chemical make-up is not stable for long-term storage. It will eventually deteriorate and release plasticizers and other chemicals into the photograph that will degrade the print over time. Safe plastics to use are polyester, most commonly called mylar or melinex. It is fine to insert prints into these sleeves, and then store in an archival box.

  • Environment: Stability is key. It is imperative to have a non-fluctuating temperature and relative humidity. That said, it is ideal to have a cool temperature and a relative humidity of less than 50%, however, keeping a stable environment is the most important. The beauty of black and white film, for me, is multifaceted, but one aspect is the longevity. Unlike a chromogenic print, a digital image, or resin-coated paper, black and white film is a survivor. When processed appropriately and stored properly, the negatives and prints will last hundreds of years. However, if squirreled away in a scorching attic, damp basement, or in direct sunlight, you will out live both the negatives and prints. So, when deciding where to store the boxes of prints and negatives, avoid the darkroom, basement, and attic; if storing in your home, a closet can be quite safe, as well as drawers in an unused dresser. Flux, unless referring to the art movement, is terrible for any artwork. A drawer or closet can provide a small micro-environment within the larger, slightly more fluctuating temperature throughout a home.

    Shrunken, irreparable negative due to extreme heat conditions

    An example of what heat can do to a negative is shown in the above image. I came across this negative in an archive of a famous photographer. Massive shrinkage occurred due to heat. Sadly, this cannot be reversed and the negative cannot be saved.

  • Stay tuned for the third (and final) part of this preservation series, which will address conservation treatment- what to do when disasters strike, how to salvage materials yourself, and when to seek professional conservation help.

    Further Reading and Resources

    Books: Adams, Ansel. The Print. Little, Brown and Company: Boston, 1983.

    Issues in the Conservation of Photographs. Ed. Debra Hess Norris and Jennifer Jae Gutierrez. The Getty Conservation Institute: Los Angeles, 2010.

    Lavedrine, Bertrand. A Guide to the Preventive Conservation of Photograph Collections. The Getty Conservation Institute: Los Angeles, 2003.

    Rempel, Siegfried. The Care of Photographs. Nick Lyons Books: New York, 1987.

    Web: American Institute for Conservation Photographic Materials Group: http://cool.conservation-us.org/coolaic/sg/pmg/index.html

    Gawain Weavers Care and Identification of Photographs Workshops: http://gawainweaver.com/

    Image Permanence Institute:

    https://www.imagepermanenceinstitute.org/

    George Eastman House:

    http://www.eastmanhouse.org/

  • Photo Preservation Guide Part 3: Handling Disasters and Professional Help

    This is the final part of a three part series on preservation; the first served as the introduction to proactively create archival prints, the second focused on handling, exhibition, storage, and environment; and this part explains the conservation treatment. If prints are processed archivally, and handled and stored properly, the most common reason a print would need conservation treatment is due to some sort of disaster. There are disasters a non-professional can handle, and ones they cannot, and below I will explain when it's time to call on a professional for help.

    photos that got wet and stuck together

  • Types of Disasters: Working in the field of preservation, I get called for all sorts of imprudent occurrences that have happened to items. A cat urinated on the photograph, the carriers truck partially exploded, a viewer showed the photographs visceral affect it had on her by spray painting it, as well as more common and ordinary manifests such as floods, fires, and fading. The field of preservation can be viewed as a type of healthcare; one must treat their items well, protect them from harm, use care to avoid the sun, go for check-ups, but also, at times, a doctor is needed.

    negatives in a bucket of wter

    Handling Disasters: Last year, a few days after Hurricane Irene plagued the east coast and flooded nearly everyone I know, I got an unexpected call from a friend in great need. The basement of his parents home in upstate New York flooded; and the basement is where his mother stored family photo albums. Now, the basement is not a place to store such heirlooms as I have explained in the second part of this series, however, the reality is that many people use both basements and attics for storage. In this disaster, everything was under

  • water, there was no electricity, and the area was in a state of emergency. So, the best advice I could give over the phone and to an untrained preservation professional, was to keep the negatives wet and begin to air dry the prints as soon as possible. Negatives can stay in water much longer than prints, so the first thing to do is place all of the negatives in a bucket of clean, fresh water, and tend to the prints. Wash the photographs in clean water and air-dry hang as one would after producing the print. During a disaster, this may be less ideal or a less archival process than one would do in the darkroom, but it saves the print! As long as it is washed in clean water and hung to dry, it prevents the photographs from sticking to one another as well as prevents mold from growing. When dealing with wet materials, it is important to keep air circulating, lights on (mold grows in moist, dark places), and monitor continuously. The prints may curl but can be flattened later. The important thing is to get the prints apart before they have time to fuse together or grow mold. Once the prints are hanging to dry, the negatives can be fully washed, put through hypo, and then dried as if processing all over again.

    air-drying prints

  • Professional Help: Almost all other disasters will require professional help. If photographs are damaged through chemical breakdowns, harmed during exhibition, killed during transportation, punctured, burnt, red wine sodden, faded, sliced, painted, placed in the oven (I have heard the most ridiculous of tales throughout the years!), a photo conservator is needed to repair the damage. Conservators are highly trained, typically embodying a fine combination of scientific knowledge and artistic ability. The conservator performs invasive single-item treatment, and in following the healthcare analogy, they are the specialist doctors, the ones you usually need a referral for. The professional organization for conservators, The American Institute for Conservation, has a website that serves as a referral for finding photographic conservators via geographic locations. One can also always call a local university, seeking out the preservation department to ask for a referral as well as share the disaster story, a tale that is always returned with sympathy by the preservation professional no matter how many he or she has heard over the years. All of this being said however, conservation is expensive and should be reserved for special, irreplaceable prints. So, take caution as much as possible in the general health and well-being of your photographs, and properly store the negatives in case disaster does strike.

  • a look inside Kate's conservation lab

  • a look inside Kate's conservation lab

    Hope you enjoyed and learned from this preservation series. Please feel free to contact me with any questions, or to share any disaster stories I never grow tired of helping or lending a sympathetic ear! Best of luck for longevity. Kate

  • Bio: Kate Contakos is Head of the Preservation Department at Stanford University, and was a founding member of Shutterclank! (film photography magazine). She shoots black and white film on her Leica, Mamiya, and Nikon, and spends lots of time in her custom built darkroom in her loft in San Francisco. She is currently addicted to Ilfords MG Art cotton rag paper.

    Find her here-

    Twitter: @contakos

    Flickr: http://www.flickr.com/photos/contakos/

    Shutterclank!: http://www.shutterclank.com/

    Further Reading and Resources

    Books: Adams, Ansel. The Print. Little, Brown and Company: Boston, 1983.

    Issues in the Conservation of Photographs. Ed. Debra Hess Norris and Jennifer Jae Gutierrez. The Getty Conservation Institute: Los Angeles, 2010.

    Lavedrine, Bertrand. A Guide to the Preventive Conservation of Photograph Collections. The Getty Conservation Institute: Los Angeles, 2003.

    Rempel, Siegfried. The Care of Photographs. Nick Lyons Books: New York, 1987.

  • Web:

    American Institute for Conservation Photographic Materials Group: http://cool.conservation-us.org/coolaic/sg/pmg/index.html

    Gawain Weavers Care and Identification of Photographs Workshops: http://gawainweaver.com/

    Image Permanence Institute:

    https://www.imagepermanenceinstitute.org/

    George Eastman House:

    http://www.eastmanhouse.org/