This video demonstrates sewing a book using two-on and three-on sewing on tapes. Two-on sewing, or the full name most commonly given to it being "two sheets on" sewing, is sewing two sections on at a time. This technique can be used on cords as well as tapes. The early use of this technique was most likely for speeding up sewing. However, for craft binders it is mostly used to reduce the swell in thick books with many sections.