aquatinta

AQUATINT'A, n. [aqua, water. See tincture.]

A method of etching on copper, by which a beautiful effect is produced, resembling a fine drawing in water colors or Indian ink. This is performed with a powder of asphalt and fine transparent rosin sifted on the plate, which is a little greased; the loose powder being shaken off, the plate is heated over a chafing dish; and when cool, the light places on the plate are covered with a hair pencil, dipped in turpentine varnish mixed with ivory black. A rim is then raised with bees wax, and reduced nitrous acid is poured on, and suffered to stand five minutes; then poured off, and the plate dried. This process with the pencil and the aqua fortis is to be repeated till the darkest shades are produced.