BPW Resident Artist Clifford Rainey is currently working with copper-plate aquatint.
Aquatint uses the application of acid to make the marks in the metal plate. Where the engraving technique uses a needle to make lines that print in black (or whatever color ink is used), aquatint uses powdered rosin to create a tonal effect. The rosin is acid resistant and typically adhered to the plate by controlled heating. The tonal variation is controlled by the level of acid exposure over large areas, and thus the image is shaped by large sections at a time.