Topics in Photographic Preservation 2007, Volume 12, Article 22 (pp. 143-143)
This is a mounting technique that has been used for medium size to moderately large format photographs (up to 110 × 80 cm approximately). It takes advantage of the contraction experimented by paper, which is more pronounced in the machine direction (in machine-made papers), as it dries. Its principle is similar to that used by artists for stretching watercolor paper (in preparation for using it as support) and by paper conservators for flattening large format prints and maps. It is also used by canvas-painting conservators for stretching wavy supports before lining the paintings.
Four paper bands (7 to 10 cm wide), to be used as hinges, are cut the same size of each side of the photograph. The hinges can be adhered to the photograph in either wet or nearly dry state (with the humidity provided by the adhesive only), but they need to be entirely moistened when attached to the rigid support. 8-ply rag board has been used as support but another type could be tried. Wheat starch paste (with or without a small amount of methyl cellulose - depending of the size and thickness of the photograph and the working time determined by the RH of the environment) has been used as an adhesive. This has been used to attach the hinges to both the photograph and the rigid support. Other water-based or water-compatible adhesives might be used.
The photograph might be dry or moist during the mounting process but the latter state will create more tension (which might be desirable or not depending on the photograph). 1 to 2.5 cm of “free” hinge must be left around the photograph; between the edges of the photograph and the area of the hinge to be attached to the rigid support. This area of “free” or loose paper creates an even tension as the hinge dries and will compensate or absorb possible dimensional changes of the photograph in the future. The outer edge of the hinge is attached (to the front) of the rigid support.
Hand-made Japanese papers of various thickness have been used as hinges, but machine-made papers might be also used for larger photographs or when more tension is required (the machine-direction of the paper must be parallel to the edge of the photograph. The hinges can be left air dry but the areas attached to the photograph and to the rigid support must dry first or at the same time than the loose or “free” surrounding zone, otherwise the tension exerted by the latter will provoke detachments of the hinge (from either the photograph or the rigid support) and consequent deformations.
Maria Fernanda Valverde
Conservator of Photographs
Papers presented in Topics in Photographic Preservation, Volume Twelve have not undergone a formal process of peer review.