Engraving is the art of incising lines, or designs, on a hard surface with a sharp tool. The engraver must hold the engraving tool in one hand while moving the whole metal plate with the other. Long shallow lines, rather than short sharp cuts, are easiest to produce with this method. While a fairly stiff crisp image results, metal engraving allows a freer line than wood engraving. To become a proficient engraver, an apprentice had to serve some seven years. Etching, while similar to engraving, differs in that the plate is incised by acid rather than by a cutting tool. The resulting image is usually light and flowing, giving the impression of freehand drawing.

Etching was easier to learn than engraving, and most bird artists of the 18th century learned to etch their own plates. It is sometimes difficult to tell by looking at a print whether it was engraved or etched, and it is not uncommon to see etchings described as engravings. In fact, a combination of the two methods was often used.

Some of the most famous bird artists of early America produced their illustrations using metal engraving or etching techniques. This exhibition begins with a display of works by three such artists — Mark Catesby, Alexander Wilson and John James Audubon. Next are examples of metal engravings by two French artists, Jean Baptiste Audebert and François LeVaillant.

Information provided by: http://rmc.library.cornell.edu