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‘Inherent Vice’ and Quality
A Photograph Conservator’s View

by Barbara E. Lemmen

In general, my role as a photograph conservator, which doesn't come into play until after the artist has created the photograph, is to stabilize the condition of damaged or deteriorating prints.  However, I often receive questions from photographers about drymounting.  When asked for advice about the creation process, I can work with photographers to educate them on the merits and permanence of specific materials and methods so that they can make informed decisions.  For example, I might tell an artist that it may not be possible to unmount a mixed-media photographic work should that become desirable or necessary in the future.  Depending on the exact circumstances and materials, the same releasing agents that break the bond of the mounting adhesive may be likely to affect some element of the photographic object.  The final artistic choices, however, must always be made by the artist.

Mounting can have many benefits for a photograph.  The process keeps the print flat by restraining it.  Otherwise, changing humidity will eventually cause most photographs, such as fiber-base black-and-white prints, to curl.  When mounted and flat, a photograph is also easier to view, display, and handle, which translates into less damage over time.  The increased support provided by the mount lessens the chance of bending and cracking, and a mount larger than the print protects its edges.

Whether you drymount your work or not the choice of appropriate materials can have an immense impact on the overall stability and longevity of an object.  When deterioration occurs because the component materials of an object are themselves chemically or physically unstable, conservators call it "inherent vice' " Poor quality mount boards that turn brittle and acidic are an all-too common example.  Therefore, conservators strive to use and recommend the most stable materials we know of, materials that have been shown through the passage of time or through modern testing to resist changing themselves or adversely affecting their surroundings.  Consequently, we often devise and prepare alternatives to the commercially available drymounting products to suit a particular problem or object.  This is not to say that you should not use readymade drymounting products or that they will damage your photographs.  I have not yet seen damage to an object from the proper application of drymount tissue; in historic objects, it has often acted as a barrier, protecting a photograph from deterioration by the poor quality mount.  Commercially available drymounting materials possess desirable properties, such as convenience and ease of use, which may make them preferable to the photographer, and their selection justifiable to the conservator.

If you drymount your photographs, use a product that consists of a thermoplastic adhesive coated onto both sides of a paper support.  Although formulations change, this type is considered to be the easiest to remove and the most stable over time.  Drymount products that are simply sheets of thermoplastic adhesive, lacking a paper layer, can be selected if the first type is unsuitable for a particular application.  The least desirable are products that are pressure-sensitive, such as spray or cold mounting systems.  All materials other than the combination of a thermoplastic adhesive and paper support are initially much more difficult to remove from the photograph.  And, since they are relatively new, little is known about how these adhesives might change as they age; it is possible that they will become difficult or impossible to reverse should future circumstances warrant removal.

 

In terms of quality, the choice of the support for the photograph is as important as how to mount it.  If it is of poor enough quality, the board can cause fading or staining in the print.  A board may also become acidic over time and discolor, changing the aesthetic of the entire object.  The physical integrity of a print is endangered when poor quality paper products become weak and brittle with age.  Unfortunately, terms such as 'archival' and 'pH neutral' tell one nothing about quality.  Look for a support with fiber stock of 100% rag, cotton, and/ or alpha cellulose to ensure the most stable and longest lasting product, whether it's labeled 'buffered' or not.  Many suppliers of conservation matboards apply the Photographic Activity Test (ANSI IT 9.16 1993) to their products; if a board passes this test, your photograph will be less likely to deteriorate over time.

 

This article was originally published in Mastering the Black & White Fine Print,
Photo Techniques
special issue #11, and is reprinted by permission of the author.
Copyright by Barbara E. Lemmen.  All rights reserved.
May not be reproduced in any form without permission of the author.

 

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