July 05, 2012

Thursday Terms: Onlay and Inlay

Today, let's take a look at some basic terminology for decorative leather techniques. Onlay and Inlay are two similar terms, both of which refer to smaller pieces of leather adhered to the cover of a book, usually to form some kind of decorative motif.
Amazing work by Monique Lallier


Leather inlays, which are similar to inlays in woodworking, are created using shaped pieces of leather, which are pared to the same thickness as the covering leather it will be adhered to. A piece of leather the same shape, size, and thickness as the inlay to be applied is removed from the backside of the covering leather, and the inlay is placed into the resulting recess. The edges of the inlay can be left raw, or be tooled, in which case a bevel is created in the edge of the inlay pieces, with the skin side slightly larger than the flesh side. This gives a smooth, well-supported surface for the impressions of the finishing tools.

A binding executed for the Koninklijke Bibliotheek by Jean Gunner


Onlays, on the other hand are very thin pieces of leather (often less than 0.2 mm) which are adhered over the covering leather on a book. Because of their thinness, the applied onlay  is not noticeably raised from the surface of the cover.. Onlays are adhered to the covering leather with paste or PVA, and their edges are usually, though not universally, tooled over in order to hide any minor irregularities. A common use for onlays are on the spine of a book, containing the title and author's name.
Paper Dragon Books

 Inlay and onlay can be combined in a more complicated design, and there are a myriad of techniques that a binder can use to create them. Design bookbinders like Monique Lallier and Paul Delrue are examples of artisans who have achieved the highest standards in both design and technique. Organizations like Designer Bookbinders and Designer Bookbinders of America both have online galleries of their member artists for your internet browsing delight.


If you're somewhat new to bookbinding, and would like to experiment with different techniques for working with leather, you may be interested in the upcoming workshop with Biruta Auna , the weekend of July 21-22, Decorative Leather Techniques. Beautiful images of her work are available here.


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