The Japanese stab binding technique is a simple way to quickly bind a book. It involves sewing all the way through a stack of pages enclosed between two covers. The traditional patterns used for ledgers and other commercial documents are fairly simple. This pattern adds a decorative butterfly to the usual stitching.
Instructions for this pattern and several variations are available in this document. These instructions assume that all stitches go all the way through the book. However, another possibility is to have the stitches comprising the butterfly pierce only the front cover. This will result in a book with the normal width spine area—rather than the extra wide one—and with the butterfly pattern only on the top of the book.