THE “PERFECT” FILL FOR THE MAGNIFICANT TINTYPE Jiuan-jiuan Chen, Thomas Edmondson, John McElhone, and Irene Brückle ABSTRACT This paper discusses the treatment of filling the emulsion loss of a tintype at Heugh- Edmondson Conservation Services and the follow-up experiments to look into the issues concerning the possible effect of the added material to the iron support at the National Gallery of Canada. The emulsion loss was filled with cast gelatin film that was toned with watercolor and varnished with Paraloid B-72 to match the appearance of the original. Follow-up experiments showed that if the iron support was not properly protected, rust might occur after the gelatin film was attached. The iron support treated with tannic acid, however, appeared to be stable in an enclosed chamber of high relative humidity for three weeks after the gelatin film was attached. The final results of these tests will be presented in the next Topics. PART I: TREATMENT The Object and Its Condition Many new conservation treatments are developed because the conservator is faced with a problem that has not been solved yet. Such is the case with the tintype in Figure 1. It is a particularly interesting image that shows seven young men wearing all sorts of different hats. The scene conveys a sense of their close friendship and the fun it must have been for them to have their picture taken at a photo studio. The plate was in good condition except the loss of emulsion and the black lacquer at both upper corners. This damage was caused by the iron support having been bent, which caused the emulsion and lacquer to release. Though stripped bare and exposed to the environment, the iron support of the damaged areas did not exhibit visible rust. It indicates that the damage happened fairly recently. This alone would probably not present a problem, since it is unlikely that the iron corrosion will continue if the tintype is kept in a well-controlled environment. Of concern to us was, however, the visual distraction of the two losses in viewing the image. In order to re-integrate the appearance of the photograph, we decided to perform a cosmetic treatment after we had obtained permission from the owner. Looking for a Solution for a “Perfect” Fill. While thinking over this treatment, we first had to consider the quality of the fill materials to be used. They had to be stable, chemically compatible with original materials, and they were not to interfere with any future treatment or scientific analysis of the original substrate. In addition to these considerations, we were challenged to find a way of making an inconspicuous and aesthetically compatible fill for this tintype. This meant that: First, the fill needed to match the thickness of the loss. Second, the surface texture and gloss needed to be similar to that of the varnished collodion emulsion. Third, the inpainting that was to be applied to the fill needed to match the continuous tone of the image. We felt that just building up the thickness of the loss with acrylic colors or pigments mixed with different binders would not give a satisfactory result.