Pouring aqua fortis on the plate The first etched prints date from the early sixteenth century. Unlike engravings, where lines were directly cut on the copper plate using a burin, in an etched plate the incisions were made using acid. First the entire plate was covered evenly with a melted acid-resistant wax ground. After this had cooled and hardened, the etcher would use a needle to draw lines through the ground, exposing the copper underneath—a far less laborious task than that of engraving directly into copper. The finished plate was then immersed into a bath of acid, the acid eating into those parts of the plate exposed by the etched lines. The longer the plate was immersed, the deeper the lines. Once this had been done, the ground was removed and impressions made from the plate using an intaglio press in the same way as engravings. Etchings can usually be distinguished from engravings by the relative unevenness of the lines in the former, particular their rounded, as opposed to pointed, ends, caused by the acid not biting completely evenly. Engraved lines look more formal than etched lines, the latter often resembling the greater freedom of drawing.