The process of stitching groups of leaves together to allow them to be sewn to sewing supports utilising the sewing techniques also used for folded gatherings. Overcasting is most often found on books consisting entirely of or with large numbers of single leaves. The most often used technique is a form of hellical stitching in which groups of leaves are whipped together along their spine edges.
Georgios Boudalis (2004) “The Evolution of a Craft: Post-Byzantine Bookbinding between the Late Fifteenth and the Early Eighteenth Century from the Libraries of the Iviron Monastery in Mount Athos/Greece and the St. Catherine’s Monastery in Sinai/Egypt”, PhD Thesis, London, University of the Arts London. http://ualresearchonline.arts.ac.uk/2298/ (accessed February 2015)
Bernard Middleton, A history of English Craft Bookbinding Techniques, New Castle, London, Oak Knoll Press, The British Library, 1994 (4th ed.)