Shagreen was traditionally prepared by embedding plant seeds (often Chenopodium) in the untreated skin while soft, covering the skin with a cloth, and trampling them into the skin. When the skin was dry the seeds were shaken off, leaving the surface of the leather covered with small indentations.
In the 17th and early 18th centuries, however, the term "shagreen" began to be applied to a leather made from sharkskin or the skin of a rayfish (probably the pearl ray, Hypolophus sephen). This form is also termed sharkskin or galuchat. Such skins are naturally covered with round, closely set, calcified papillae called placoid scales, whose size is chiefly dependent on the age and size of the animal. These scales are ground down to give a roughened surface of rounded pale protrusions, between which the dye (again, typically green vegetable dye) shows when the material is coloured from the other side. This latter form of shagreen was first popularised by Jean-Claude Galluchat (d. 1774), a master leatherworker in the court of Louis XV of France. It quickly became a fashion amongst the French aristocracy, and appears to have migrated throughout Europe by the mid-18th century.
In medicine, a shagreen patch is a patch of shagreen-like rough skin, often on the lower back, found in some people with the genetic condition tuberous sclerosis.