Daniel Hopfer, Emperor Charles V, 1520 (or 1521?); printed 1684, etching (iron) with open biting, National Gallery of Art, Washington. https://dartabase.art/cite/nga/8003

Daniel Hopfer, Interior of the Church of Saint Katherine with Parable of the Pharisee and the Publican, c. 1530, etching (iron) with open biting, National Gallery of Art, Washington. https://dartabase.art/cite/nga/8001