Metal engraving and etching by hand on copper plates were the methods used for most natural history illustrations in the 18th and early 19th centuries. Engraving on copper required the artist to incise an image on a hard surface with a sharp tool. Long shallow lines, rather than short sharp cuts were easiest to produce with this method. It took years for an apprentice to become proficient.

Etching, while similar to engraving, uses acid to incise a metal plate rather than a cutting tool. The resulting image gives the impression of freehand drawings. Because it was less labor intensive than engraving, many artists learned to etch their own plates. Often a combination of the two methods was used.