What is a girdle book? It is not an undergarment! A girdle book is one which has an extra protective covering of soft leather made in such a manner that the book can be hung from the girdle or habit cord of a cleric and swung upward for reading while still attached to the girdle or cord. The Spencer Collection of the New York Public Library has a girdle book which is a brevarium, manuscript on paper, written in Southern Germany, probably in the monastery of Kastl, in 1454. The manuscript is bound into a pouch of soft doeskin. Its 457 leaves of antique paper measure about four by five inches. It has four pasted-in woodcuts; except for one passage, it is in Latin. Capitals and chapter beginnings are rubricated, and a calendar precedes the text matter.

Goatskin is applied over thin boards, the actual cover of the book; it is laced with cords, and then covered with an envelope of doeskin. This outer doeskin gives the book its distinctive appearance, the lower part extending some eleven inches; the leather is then gathered into a braided knob to simplify carrying the book by hand or wearing it on a belt. Doeskin and deerskin were frequently employed for this type of binding, which was used in the middle ages and early Renaissance, especially in Germany. Devotional books or didactic works, or professional reference books, for example, law books, were most often bound in this manner, and the bindings were often quite unpretentious. Some very elegant bindings, however, were produced in velvet and brocade, to protect illuminated prayer books. Few intact girdle books have survived, as the overlapping leather was usually cut off for reuse when the need for protection of the volume had passed. Girdle books are also sometimes referred to as "utilitarian protective bindings.", “book pouches”, and a French term which translates as a “tailed binding”..

There is a scarcity of literature about girdle books, we were delighted to discover the source of the preceding information, "Bookbinding and the Conservation of Books", by Matt Roberts and Don Etherington., published by the Library of Congress, Washington, 1982, and from an article in “American Book Collector” by Walter Hart Blumenthal

(This article was published in "The Microbibliophile: A Bi-Monthly Journal About Miniature Books").