Drypoint
Once most of the linear work had been completed using etching, Goya sometimes used drypoint to accentuate areas of the composition. He used this technique to emphasize the shoulder of the matador on the right in Banderillas de fuego (Banderillas with Firecrackers). (See figs. 13 and 14). A drypoint needle is rounded to a point and is pushed with greater force into the surface of the copper than the etching needle, because, while etching produces a line by physical and chemical action, drypoint produces a line by physical force alone.
The shape of the drypoint line varies depending on the angle the needle is held, but the goal is to plough through the copper, so a furrow is created and the copper that is dislodged creates a burr on either side. When ink is applied to the plate, it settles down in the furrow and on the burr creating a beautiful velvety line with soft edges. The blurring of the line is the most distinctive feature but, in some instances, where Goya wanted to discreetly rework an area of etching, he might add drypoint lines and burnish them to remove the burr.36 Given the softness of copper, the drypoint burr is quite vulnerable to wear and over time, as more prints are pulled from the plate, the burr will gradually be worn away causing the printed lines to resemble etched rather than drypoint lines making it difficult to differentiate between the two processes. These signs of wear on a plate are transferred into the print and can be used to help identify earlier and later impressions.
Tomas Harris, op.cit., p.23.