Aquatint:It is an etching process on copper or steel by means of nitric acid. In this technique, a thin layer of resin dust is sprinkled on the plate and heated to make it adhere.

• 水彩色调:用硝酸在钢片或铜片上作腐蚀的蚀刻法。这个技巧是在版面上洒上一层薄薄的树脂粉，加热把它粘附于版面。