Engraving plates are quite sturdy. When treated with respect they can last indefinitely. Several publishers are still printing today from eighteenth, nineteenth and twentieth century plates that keep appealing to modern tastes. The process Old engravings were usually made after a painting, watercolor or drawing. In spite of the name, both engraving and etching techniques were used, often on the same plate.
Acid eats away the metal where it is exposed.
In the nineteenth century the photogravure process was also used. This entails transferring an image to light-sensitive chemicals on a copper plate by use of photography, and letting acid etch the exposed surface. A contemporary printer prepares and prints the engraved plates, still by hand. These prints are usually hand watercolored. Printing engravings is demanding work.