This is the first in a new series of articles about conservation written by professional conservators. We hope you will find them interesting, and welcome any comments, questions or suggestions you may have for us.
The artwork's treatment that I am going to describe here is an interesting case study because it is such an extreme example of the horrors which can lurk behind a picture's seemingly innocent window mat.
Before treatment, front and reverse
After treatment, front and reverse
"Thoughts of Birds", by Mungitok, is printed with heavy layers of ink on thin Japanese style paper. This gives the print an inherent tendency to ripple -- the paper will expand and contract with variations in humidity, while the ink will not. The paper support is discolored overall, and has a darker band of acid mat burn around the opening of the window mat. These are common enough problems, and relatively straightforward to treat. What sets this print apart is the fact that its margins have been glued to the window mat with shellac, green oil paint and masking tape. The "adhesives" have completely soaked into the paper, turning it brown and brittle. There are also large losses at the edges of the margins.
The unusual nature of this damage presented a special challenge. After testing, I discussed treatment options with the owner. The following is a much-condensed version of the actual treatment.
The mat board was first thinned down to its facing paper, and the shellac and green paint reduced with acetone, taking care to avoid the image area. The masking tape adhesive had hardened to a rock-like consistency and had to be softened with heat to allow the paper carrier to be removed. The adhesive was then reduced on the suction table using a variety of organic solvents. Floating the print on a distilled water bath and bleaching with light reduced general discoloration and mat burn. The margins, which were very fragile, were lined with a thin Japanese tissue using wheat starch paste, and losses filled with Japanese paper inserts. The print was then stretch dried to flatten it as much as possible. The final result, while not a total resurrection, greatly improved the overall appearance and longevity of the print.
"Every Piece is Different" is a golden maxim of conservation and "Thoughts of Birds" illustrates this point perfectly. Although I have worked on different editions of this same print, I have never before seen shellac and paint used as adhesives. I probably never will again.