I first noticed what I call “naturally packed sewing” on an early 16th century quarto. Usually, a pack sewn book has extra windings around the cords to fill them in even with the thickness of the signatures. I believe it was Peter Franck who first described pack sewing, which he called “arch sewing”. For naturally packed sewing, if the sewing thread is fairly soft, and the signatures relatively thin, the paper pretty thin, the book can be sewn packed without additional windings. Here, there are 39 signatures and 39 windings around the double cords. This image is larger than life size.
The paper is 60lb. Mohawk Vellum Soft White from New York Central Art Supply. Folded down to quarto, 2 folios, 4 leaves, 8 pages.
The cord and thread are from Colophon Book Arts Supply. The cord is Garniture Linen Cord, the thread Londonderry Linen, Ash Grey, 18/3.
Peter Franck. A Lost Link in the Technique of Bookbinding and how I Found It. Gaylordsville, Conn: n.p., 1941.