Aquatint is often used as part of the etching process. Aquatint enables tonal areas to be added to an etching plate. The plate is covered with powdered rosin, the rosin is fused onto the plate over heat. The plate is immersed in acid, and the acid bites between the microscopic dots of powder. The longer the plate is left in the acid, the deeper it will bite, making the aquatint darker.
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