Antique etching Pia (Vue générale du genre). "Pine (General view of the genus)". Engraving work on copper. There is an author's signature and year. France, 19th century.

Etching is an engraving on copper with poisonings etched with acids. A sheet of paper saturated with moisture is glued onto a cleaned polished board and printed under pressure, rolling the rollers of the machine. The first boards were copper plates. The name of the technique is copper engraving.