Gilt Edges

Beginning in the fifteenth century, the most common edge decoration on a book was gilt edges. Gold, being very malleable, is beat into very thin sheets (“to airy thinness beat” as John Donne put it in “A Valediction: Forbidding Mourning”). The gold is then applied to the book’s edges using an adhesive size that is often made of egg white and water. Gilding is not simply decorative. In addition to giving the edges a beautiful golden luster, the gold creates a metal layer that protects the paper (or vellum) from dust and moisture. 

Pliny, the Elder. L'Histoire dv monde de C. Pline. Lyon: Claude Senneton, 1566.

Gilding edges is one of the most traditional ways of beautifying a book. The long edges of these sixteenth-century volumes of Pliny were gilded when they were rebound years later and have not lost their spectacular shine.