PHOTOS AND ART on paper are sometimes backed onto rigid materials. This practice first gained wide popularity in the 19th Century, when machine made paperboards became readily available. Wet (paste or glue) and dry (heat activated) adhesives have been used to attach art to backings, each coming with its own set of advantages and drawbacks. The obvious purpose of backing art is to keep it flat. Why then would one want to remove it?
The usual reason is stabilization. Although high quality, chemically stable paperboards are easily available now, this was not always the case. The majority of paperboards used in the past were made of poor quality, acidic wood pulp with unstable sizes. Volatile acids and peroxides generated by these paperboards often discolour and weaken artworks. Poor quality paper boards can also, over time, become quite fragile. It is not unusual to see artworks broken and cracked when their brittle backing boards snapped. Stronger materials like plywood, chipboard, masonite, and doorskins, have also been used for backings. These usually dont break, but they do emit volatile pollutants which damage and discolour paper and media. Poor quality adhesives like rubber cement and early shellac-based drymount tissues can also stain and damage artworks.
Another reason to remove a backing is to ready an artwork for conservation treatment. Overall discolouration, stains, and tears are most easily treated without the complication of a backing.
Backings affect the look of art on paper, and there are cyclic trends in the popularity of backed and unbacked works of art on paper. Mountings which are not original to the art may be removed in order to regain the more relaxed look of a free sheet of paper. Monetary value is also a consideration when deciding to keep or remove a backing. A watercolour with an original, artist-applied backing might be devalued if the mount is removed. Alternatively, removing a backing that is not original, and interferes with the intended look of the piece, can increase the value of an artwork.
After weighing the pros and cons, the owner may decide to have a backing removed. How is this done? Usually, the first step is to thin the backing as much as possible, to allow easier access to the adhesive. If the backboard is laminated, it can be split along a ply line. This makes it a simple matter to save important inscriptions on the reverse of the board, or gallery labels for later encapsulation. If the board is unplyed, saving inscriptions, etc., is a bit trickier, but still almost always possible. Unplyed boards are peeled down bit by bit until there is only a thin layer of paperboard and/or facing paper left.
If the binding adhesive is water based, paper and adhesive residue are softened using moisture and sometimes heat, and slowly removed from the reverse of the art. Drymount adhesives can usually be softened with organic solvents but polyvinylacetate emulsions (white glues, like Elmers) are permanent.
Backing removals can be time consuming, but most paper conservators enjoy this alpha-wave inducing task. Occasionally, backing removals reveal hidden inscriptions and sketches on the reverse of the artwork, giving a rewarding sense of discovery and connection with the artist and their art.
Conservation is an engaging combination of science, art and a participation in the guardianship of artwork and history. For more information visit the FACTS (Fine Art Care and Treatment Standards) website at www.artfacts.org.
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