Stamping of a gilt surface by numerous tiny points, rings, x-shapes or clustered points into a texture with the purpose to “sparkle like a millet grains’” according to Cennini. Two main techniques of granulation were employed, “all-over stamping” (granare a disteso) and “stamping in relief” (granare a rilievo).

Source: Skaug, Erling. Punch Marks from Giotto to Fra Agelico: Attribution, Chronology, and Workshop Relationships in Tuscan Panel Painting: with Particular Consideration to Florence, c.1330-1430 (Oslo: IIC, Nordic Group, the Norwegian section, 1994), p. 12.