Saint Jerome, c. 1520, Master of 1518, Dutch, Netherlandish, c. 1470-c. 1527, 8 3/16 x 8 3/16 in. (20.8 x 20.8 cm) (sheet, tondo)16 1/4 × 16 1/4 × 3/4 in. (41.28 × 41.28 × 1.91 cm) (outer frame), Pen and brown ink, Netherlands, 16th century, This design is for a type of stained glass produced in the Low Countries during the early 16th century. The panes were often circular and small. Such a highly finished drawing might have been shown to a patron before work began on the glass itself. The artist was a productive Antwerp Mannerist painter whose works lack signatures or other documentation. Historians assigned the name Master of 1518 based on the date inscribed on one of his altarpieces.