Rembrandt famously combined drypoint with etching in many of his prints.
Drypoint involves scratching directly into a metal plate with a sharp tool. The resulting burr holds ink and can create soft, velvety lines. Etching, by contrast, uses acid to bite lines into a plate through a protective ground. Rembrandt used both methods, sometimes adding engraving or plate wiping effects.
His inventive printmaking helped make him one of the most influential print artists in European history. He repeatedly reworked plates, changing details, shadows, and figures between states of the same print.
The Three Crosses and Christ Preaching are especially well known for their complex combination of etching and drypoint. Drypoint is sometimes mistaken for engraving, but engraving cuts directly into the plate with a burin and produces a different line quality.