Bookbinding
"Historical. As a protection for medieval manuscript books thin wooden boards were used for covers and during the early Middle Ages these were given a full leather covering to join across the spine the back and front board, thereby giving rise to full binding in the modern sense. Deerskin, sheepskin and pigskin were used; calf was introduced in the 15th century when sheepskin and parchment bindings also became popular. [...]
"If cloth is substituted for leather we have a cloth or half-cloth binding, and if only boards and paper are used the term paper boards applies. If the covering is of paper without boards we speak of paper covers.
"Before the invention of printing books were relatively scarce and valuable, rarely found in large enough numbers to warrant their being shelved in vertical rows. Books were kept laid flat on shelves in a cupboard (amarium) are on reading stands, and ornamentation, if any, was concentrated on the front cover which, in the case of Bibles and Gospels for altar use, might receive the skilled attention of a jeweler. When decorated, leather bindings would be stamped in relief with dies or panel stamps. About 1500, roll tools for impressing continuous patterns were introduced. [...] When the custom of shelving books vertically spread they were often placed with the spine innermost, the title being inscribed on a small piece of vellum stuck on the cover or written on the fore-edge. By 1560, however, books were generally shelved as now, and it was a natural consequence to decorate the spine.
"Lettering on the spine is thought to have been introduced about 1535. As the leather cover was attached direct to the back of the stitched sheets the raised bands divided it into panels where lettering and tooled patterns were placed.
"Practical. The main stages of hand-binding; are: folding the printed sheets into sections, gathering these in sequences, beating or rolling, collating sections and plates or maps, pressing, knocking up and marking up for sewing. There are two methods of sewing: ordinary;, for which grooves are sawn in the back to take the cords and kettle stitches. Sewing thread goes in and out of holes pricked along a section passing over but not round the cords. In flexible; work there is no hollow and no saw cuts are made in the back (to which the covering leather will be stuck direct). As sewing proceeds thread encircles each of the four or five cords and terminates in a kettle stitch which links one section to the next. End-papers are attached, the back is glued, rounded and put in a press to form the grooves in which the edges of the two book boards will fit. Boards are lined with paper on one or both sides, cut to the final size and attached to the body of the book by lacing on. Cord ends are pasted, tightened and hammered flat. The book is pressed. Then top-, tail-, and fore-edges are cut in a cutting press: this is known as cut in-boards.
"Book edges are next coloured, marbled or gilded. Headbands are fixed and the book is covered. Collectively, the foregoing are known as forwarding. Finishing, which follows, is the lettering and creation by a skilled craftsman of a design on the cover, worked with heated hand-tools and often onlays of coloured leather. End-papers are stuck to the inner sides of the boards, the spine and covers are polished and lightly varnished, and the book is pressed."
(Glaister, 55).
Note: for a visual exploration of book binding, we recommend Princeton University Library's "Hand Bookbinding" online resource.