Use of Leather
Vegetable-tanned leather is a sumptuous covering material for books. When wet with paste, this precious material can be molded beautifully around the endcap and spine of a rounded and backed textblock. Later it dries tight and hard to the boards and spine. One challenge of this traditional binding process, however, is that it is very wet, causing the leather to swell considerably. The subsequent shrinking of the leather as it dries requires counter-lining to flatten the boards. Binders have experimented with using the adhesive PVA in an attempt to reduce the amount of water involved but PVA doesn’t allow the leather to become as malleable, and the results are often disappointing.
Aside from the challenges presented with such a wet process, vegetable-tanned bookbinding leather is very costly and is offered in a limited pallette of colors and finishes. Chrome-tanned leather, on the other hand, has wide commercial use, is relatively inexpensive, and is available in a large selection of colors and finishes. It does not, however, absorb water so it may not be used in the same manner as its more expensive counterpart. On the other hand, chrome-tanned leather can be used the same way that book cloth and paper are used to cover books, namely, in case binding structures. All these considerations led Kelm to experiment with various leathers, adhesives, and structures in order to achieve an elegant leather binding that is not so costly or difficult to achieve as the traditional marriage of vegetable-tanned leather and rounded and backed textblock.
Students will create one textblock and two flatback cases with offset spine attachment (inspired by Gary Frost’s Sewn Boards Binding). The textblock will be sections sewn with linen thread. Folding, gathering, endsheet construction, punching, and sewing will be taught. One of the two cases will be covered with chrome-tanned leather and the other with vegetable-tanned leather. Two forms of PVA, one wet, one dry, will be compared and contrasted—Jade 403 and thermoplastic adhesive film. Kelm will teach how to flatten an undulating piece of vegetable-tanned leather into a flat sheet so that it can be used in the same manner as book cloth or paper. Students will choose which case to attach to their textblock. Making two cases gives participants all the experience and information they need to work in the future with either type of leather. And the results will be elegant!