The author analyzes the structure and function of two forms of historical paper case binding: an Italian 17th-18th century form similar to the limp vellum model and a German 18th-19th century lapped binding with heavy paper spine overlapping the inner side of the boards. He describes modifications of these two styles for conservation rebinding purposes, which omit slips and sewing supports (cords, thongs or tapes), and rely on flexible synthetic adhesive to attach book and cover, leaving both the spine and the hinge area free of adhesive. Rounding and backing are done without hammering. Strong handmade paper and linen are used for covering because they are sympathetic, durable and inexpensive. See also AATA 20-1551.