Saturday, 28 January 2012

The First World War From Above


Saturday, 21 January 2012

Preserving & Protecting Photographs

1. Natural (and not-so-natural) Enemies of Photographs

The physical enemies of photographs include obvious villains (like direct sunlight, insects and rodents) and those that are more subtle: adhesives that degrade over time, sulfur compounds that can be given off by wood or rubber and trigger fading, and high humidity that can encourage mold growth.

Experts advise against storing photographs in basements, attics and garages. They recommend storage materials specifically designed for long-term stability (called "archival" products). Surprisingly, many of the products sold by frame shops and retailers contain materials like high-acid wood pulp and Polyvinyl Chloride that can trigger deterioration.

So the first set of recommendations is based on common sense: use archival materials and keep your photographs away from bright light, widely fluctuating humidity, and extreme temperatures.

2. Small-format Photographs: Cartes de Visite, Cabinet Cards, Stereo Views, Postcards

We've seen valuable 130-year old tintypes ruined by being placed in clear vinyl album pages (the type sold for baseball cards) and then left to cook in the sun at an outdoor antiques market. In other instances, stacks of tintypes and cartes de visite removed from the protection of their original albums are pored over by one collector after another--with the images rubbing against each other and accumulating bends and scratches.

Fortunately, there are alternatives. Several types of clear plastic sleeves are available in the right sizes for cartes de visite, cabinet cards, stereo views and photographic postcards. Archival materials used for this purpose include polypropylene and polyester film (Mylar is the best-known trade name.) Both of these plastics are considered stable for long-term use. The polyester sleeves offer improved clarity.

Sleeved photographs can be stored in archival file boxes. The least-expensive type is made from "safe" cardboard with metal reinforcements in the corners.

Sleeved cartes de visite and cabinet cards can often be inserted into antique albums, providing a degree of protection from stray fingerprints and dust. However, the albums may not be chemically inert and in our experience, are usually too fragile to survive much use.

3. Family Albums and Collections of Loose Images

Family albums and collections of loose images need to be organized as well as protected. Loose-leaf albums are great for organizing. However, many commercially-available albums, as well as the familiar old photo albums with black paper pages, are considered potentially hazardous because they may have been made of unsafe materials. "Magnetic" photo albums can leave adhesive residues on images, and vinyl album pages can give off harmful fumes.

When the albums or collections consist of a mixture of sizes and formats, the photographs can be arranged on archival paper pages and mounted with archival photo corners. Then the completed pages slide into clear polyester or polypropylene pockets, prepunched for three-ring binders. Most large office supply stores carry boxes of page protectors. Look for products made of polypropylene that are labeled "archival" or "archival safe."

Even recently-made photographs in standard sizes (3" x 5", 4 " x 6", 5" x 7") can be stored safely, by using multi-pocket album pages made of inert polypropylene instead of non-archival PVC plastics.

4. Unmounted Albumen Prints

Unmounted albumen prints (and those that have been removed from old, deteriorating mounts) provide a special problem: they have an alarming tendency to curl. Some collectors and institutions hinge them at four corners, but we believe we've stumbled onto a much better solution: carefully slip each print into a strong, crystal-clear polyester envelope. The envelope can then be attached to a piece of mat board with a hinged overmat, and framed if desired. This holds the image flat and provides support for the print; the envelope can not be seen once the print is framed.

Of course, polyester envelopes containing unmounted albumen prints can be kept unmatted in an archival box, avoiding the weight of the mat board.

Fragile photographic prints on materials other than albumen paper can benefit from the same treatment.

5. Larger Photographic Prints

Have a stack of larger photographs? You'll get the most protection for the money by putting each one in a separate polyethylene bag. This is a quick solution for images that are not going to be individually matted.

For the best presentation, each photograph (including its original mounting board, if present) should be attached to a 100% rag acid-free mat board, with a window-mat of the same material hinged to fold over it. Use acid-free linen tape to hinge the two mats together, and archival mounting corners to hold the photograph in place. The window-mat hides any imperfections on the original mount. It also keeps the photograph from coming in contact with the glass of a frame.

Some experts recommend NON-BUFFERED 100% rag materials for albumen prints, salt prints, cyanotypes and color photographs. For other types of photographic prints, buffers in the mat board provide protection from acids in the environment.

Appropriate mat boards are not available at all custom framers, but many will be willing to cut and fit archival materials provided by their customers.

Because wood can give off harmful chemicals, most experts advise using metal frames.

When displaying photographs, please be aware that exposure to sunlight or unfiltered fluorescent lights can cause or accelerate fading. Ultraviolet-filtering acrylic sheets can be used in place of glass in frames, reducing the risk somewhat. Under no circumstances should photographs be placed in direct window light. This is especially important for very early images and for color prints.

For storing matted and unmatted prints, choose archival boxes -- either those with metal corner reinforcements, or the pricier (but better-looking) archival portfolio boxes.

We've also found polypropylene boxes at office supply stores and retailers like Target. They have tight-fitting lids and come in a variety of useful sizes. The manufacturers don't claim they're archival, but chances are they'll be better for storing photographs than old shoe boxes or packing boxes made from corrugated cardboard.

How do you tell if a plastic box is made from polypropylene? Look for the recycling symbol on the bottom, with the number 5 and the letters "PP".

6. Special Cases: Daguerreotypes, Ambrotypes & Tintypes

Daguerreotypes, ambrotypes and early tintypes were usually sold in small folding cases. The cases were designed to keep the fragile surfaces of these images safe behind glass. Over the years, the cover glass in a cases can crack or become dirty. Some researchers report the glass itself can deteriorate, causing damage to the surface of daguerreotypes.

Many collectors and conservators choose to replace the old cover glass. This is an operation that requires EXTREME CAUTION. The fragile surface of a daguerreotype has been compared to the delicate wings of a butterfly--one inadvertent touch and it will be marred forever. Removing the image from its case also requires care, because a slip can permanently bend a daguerreotype or tintype...or crack an ambrotype. One other potential drawback to replacing the glass: some collectors put a premium on daguerreotypes that have their original paper seals intact. If the seal is present, breaking it to replace the glass may have an impact on the image's market value.

When in doubt, consult an expert...

Originally published by The American Photography Museum