In my last article, I wrote about the case against heavy backings for posters. Now I will write about an instance where backing a poster (actually poster fragments) was absolutely necessary.
A few years ago a client brought in pieces of a very rare poster protesting cheap sugar imports from China. The fragments were found between the studs of a house that had belonged to an employee of Rogers Sugar. They were heavily coated with soot, and discoloured. The worst areas were stained and weakened by mold. The fragments were unmatched sections from several posters. Of the six received, four could be overlain to create the illusion of a single whole poster.
A fragment of poster before treatment
The first step in treatment was to reduce the very heavy black surface dirt. The pieces were first wiped with several dry Swiffer cloths. They were then rubbed very gently with grated art gum eraser to remove as much residual dirt as possible.
The paperboard backings were dampened and carefully removed, and the fragments washed in several successive distilled water baths adjusted to pH 8. Washing removed an unbelievable amount of soluble discoloration, but did not return the paper to a pristine condition. No further attempts were made to clean the paper because it was so fragile.
To strengthen the fragments, they were backed with a thin handmade Japanese paper, using wheat starch paste. Holes and losses were filled with either wet pulp or paper inserts, and then the fills toned and inpainted with watercolour. The fragments were then given a second backing of heavy weight Japanese paper to increase strength and rigidity. Should the poster require conservation treatment in future, the heavy paper can be removed without disturbing the thin primary backing which literally holds all of the bits and pieces together.
The fragments were then placed in an overlapping arrangement, so they could be read as a whole poster. They were hinged top and bottom to an 8-ply alpha cellulose backboard, and horizontal strips of archival quality Mylar run across the fragments to keep the edges of the centre pieces from lifting up. (The reflection during photography causes these strips to appear white at the left of the after photograph).
The moral of this story is never say never. It is important to know the general rules of good conservation practice, but every object and every treatment is unique.
For more information visit the FACTS (Fine Art Care and Treatment Standards) website at www.artfacts.org.