Burin engraving on copper, printed in one black ink on laid paper, with the plate mark pressed into the sheet. A goldsmith's craft that became an art in 1430s Germany, and after Dürer the way Europe reproduced and circulated pictures for three centuries.
A burin cuts a furrow, so tone has to be built from line: parallel cuts that curve around the form, lozenge cross-hatching only in the deepest shadow, and the swelling line, thick and thin along its length, that Cort and Goltzius turned into virtuosity. The caption credits who drew and who cut.
Each face of the figure gets its own burin cuts laid in the face's surface plane. The face's tone picks one to three hatch sets of swelling lozenges. The likeness is inked with the pen helper, the cast shadow is hatched, and the plate sits in a bevelled mark with a Latin caption and plate number.