Hinging allows the picture to hang freely in the mat and permits the paper to expand or contract without stress as the atmospheric conditions vary. Use instead a good quality gummed paper or a Japanese paper applied with starch paste. Gummed paper may be cut in strips one-half inch in width, of whatever length is demanded by the size and weight of the picture to be supported. The strips are folded in half and applied first to the picture and then to the backboard. Gummed paper or cloth hinges are simple and quick to use, can be removed easily, and are less dangerous in the hands of an inexperienced worker than hinges that must be applied with paste.
Hinges made of Japanese paper take more time and practice to apply.
Select a Japanese paper whose weight matches the picture, and do not apply the paste too thickly or the picture will buckle around the hinge. After attaching the hinges, cover them with blotting paper held down by a light weight for a few hours until they are dry. The best adhesive for hinges is made from starch, preferably wheat or rice. Let it stand for a few minutes to allow the starch to become thoroughly wet. Cook over barely simmering water for twenty to twenty-five minutes, stirring frequently.