Conservation Tip: Creating a simulated grain; or novel uses for a belt sander in conservation

by Dan Paterson, Assistant Chair, Potomac Chapter

This experiment in creating a false grain for a re-backing leather was inspired by a conversation with Renate Mesmer. She had been looking for a way to create a simulated grain on a cast composite repair for a 19th century cloth spine and used the belt from a belt sander as her mould. (For a fuller explanation of cast composite repair techniques see the Book and Paper Group Annual, 2010, Grace Owen and Sarah Reidell, pp 98-105.) She was pleased with the results and showed them to me. Several months later, I was doing a leather re-back on a 19th century photo album. The sheep skin had a distinctive pebbly grain pattern and none of our leathers had similar surface characteristics. I decided to follow Renate’s belt sander example since the finish was similar to the cloth binding. I selected a piece of goatskin to use and pared it as usual. Once pared, I dyed it to achieve a close approximation of the original skin. When satisfied with the color, I got the skin damp and placed the belt sander belt against the grain, put them between blotters and pressing tins, and put everything in the press under moderate pressure for 30 minutes. The result was a surprisingly close approximation of the grain on the original skin. It was by no means an exact match, but it created a much less noticeable transition between the original leather and new when placed side by side on the book. I was concerned that during the actual re-backing the embossed pattern would be lost through wetting out and manipulating the skin. Predictably, some of the pattern was softened, but it retained most of its character and made a sympathetic repair. Pictured below is a piece of the leather. On the right is the original grain pattern and on the left is the embossed finish from the belt sander.

* This article was originally published in the Potomac Chapter September 2011 newsletter, Volume 7, Issue 2. Thanks to Dan Paterson and Linda Hohneke, Potomac Secretary and newsletter editor, for allowing us to republish here.