This article first appeared in the Spring 2014 edition of 'The Gold Leaf' and appears here with the kind permission The Hand Bookbinders of California

"David Lanning of J Hewit & Sons Limited, leather manufacturers, expanded on a discussion on the Guild of Book Workers listserv on the topic of measuring the thickness of leather"

David Lanning - Sam Ellenport and I had some tongue-in-cheek exchanges about the way leather thickness was measured. I do, however, believe that leather thickness should be measured using linear dimensions, and not weight. Millimeters would be my first choice, but at a push, inches would suffice!

Gold Leaf - How have skiving machines changed over time to shave the leather to consistent thicknesses? Historically, has this been done by the operator's experience or by 'feel'? Are you aware of a time when specific measurements (of any type) came to be in wide use?

Shaving Machine

David Lanning - Hewits do not have a splitting machine, as traditionally we have always shaved our leather. I have discussed this matter with colleagues, and we believe that we have been shaving and buffing our leather since at least the 1930's. Prior to that time, leather would have been taken down to substance, using specialized shaving knives. As far as we know, we have always had to supply leather shaved down to a specification. Without this process being done (either mechanically or by hand), the leather would be too thick for purpose.

Buffing Machine

Gold Leaf - Are there different leathers that can be shaved to different thicknesses? Is this based on the type of animal or the type of tannage, or both?

David Lanning - We supply our leather to standard thickness, normally 0.6 - 1.0mm. These thicknesses are those we feel to be ideal for bookbinding and/or restoration and take into consideration the animal and type of processing used. So for example, there would be little point using full-grown cowhide for bookbinding, as by the time it is thinned down to a usable substance, all the strength as been taken away and one would be left with a Cow Skiver.

Gold Leaf - As a producer of bookbinding leather, have you seen the use of leather to various thicknesses change over time due to trends in binding styles?

David Lanning - Yes. The was a time when leather was pared too thinly. In my opinion, this was due to the required aesthetic of producing bindings with crisp, square boards. With hindsight, one can see that these bindings from the 19th century have, as rule, fared very badly. Some binders still like to use this very leather, and time will tell as to whether these are good decisions or not.

Measuring Machine

The Hand Bookbinders of California - gathered for the first time in 1972. A close-knit group of hand bookbinders, with shared interests in creating and collecting fine bindings, joined together to promote hand bookbinding and related book arts and to exchange information and ideas. HBC membership now includes students, makers of artists' books, collectors, conservators, papermakers and paper decorators, fine printers, printmakers, writers, book dealers and other lovers of the book arts. From the start, the goal of the Hand Bookbinders has been to share knowledge and members now enjoy a calendar of events including workshops at the San Francisco Center for the Book, lectures, social activities, exhibitions, out-of-town trips, plus a unique connection to the variety and vitality of the book-arts community throughout California. The Hand Bookbinders of California meet monthly and sponsor workshops and classes. Further details from www.handbookbinders.org.