Etching, DRY

-POINT. This is not true etching. A copper plate is placed in a bath of very weak nitric acid for two minutes, and then washed in water. This gives the plate a darkish tone without affecting the surface otherwise. The drawing is made on the plate with the etching points, and the strongest lines are scratched deeply into the plate, making the bur high, as no metal is removed from the plate, it is only displaced. In printing, the burs hold a certain portion of the ink, which gives a velvety tone in connection with the line. The life of such a plate is short, the bur being soon destroyed in the printing proce es.