Copper Etching: Not Just For PCBs January 13, 2014 by James Hobson 29 Comments [Morag Hickman] is an artist who makes use of ferric chloride for something other than etching a PCB.

Much like etching a PCB, Blake started with a copper sheet, writing and drawing his works backwards with stopping varnish, an acid-resistant varnish that sticks around after a nitric acid bath.