Etching Zinc with Copper Sulfate Mordant

We designed a series of experiments to determine if a copper sulfate mordant was effective on zinc plates with acrylic based grounds. Zinc is a popular plate material but cannot be etched safely using Ferric Chloride. However using Copper Sulfate Mordant (50gm salt + 50 gm copper sulphate + 1 liter H20) to etch Zinc is a safe alternative method. Our experimentation answered how Copper Sulfate Mordant effects the acrylic grounds that we usually use with Ferric Chloride. We determined ideal etching times for BIG (Baldwin Ink Ground), Z-Acryl Aquatint and Stop-Out, and Lithographic crayon resist. We re-grounded previously etched plates and also developed a practical vertical tank set-up for etching. Also we learned to identify when the Copper Sulfate bath needed to be changed and how to remove etched particles from the Zinc plate.

Research Project Tests