This appears to have been the usual system as long as books were kept in coffers or _armaria_; but when open bookshelves with chained books came into use, about the time when printing was invented, the title of a book was usually written on the front edges of the leaves.
At that time books were set on the shelves in the opposite way to that now used, so that, not the back, but the edge of the volume was visible.
Towards the close of the fifteenth and throughout the sixteenth century, the front edges of printed books and manuscripts were sometimes decorated with painted illumination, usually a portrait figure of the author of the work or some object illustrating its subject[296].
The parchment which was used to cover the oak bindings of manuscripts was often coloured by staining or painting; red and purple being the favourite colours. Chaucer, in the Prologue to the _Canterbury Tales_, describing the Clerke of Oxenford says,
For him was lever have at his beddes heed, Twenty bookes, clothed in blak and reed Of Aristotil and of his philosophie Then robes riche or fithul or sawtrie.
In some cases the oak covers of manuscripts were not hidden by leather, but were decorated by elaborate paintings. A very interesting series of folio account-books of the Cathedral of Siena, now preserved in the _Opera del Duomo_, are specially remarkable for their pictured bindings. These manuscripts date from about 1380 to 1410, one volume being devoted to the expenses and records of each year. On one of the covers of each is a large painting on the oak, frequently of a view of some part of Siena or of the interior of the Cathedral. Very interesting evidence with regard to the old fittings of the high altar, with Duccio di Buoninsegna's great retable, and the original position of the magnificent pulpit are given by some of these pictured covers. One volume of this Sienese series is now in the South Kensington Museum.
In the fourteenth century bindings of books began to be decorated by stamping patterns with dies or punches on the vellum or pigskin covering of the oak board; a method of decoration which was greatly elaborated and developed in the sixteenth century, especially by the German and Dutch bookbinders.