Tips for Etching Gold

Hello,

I am trying to etch a piece of flat sheet 14K yellow gold, and my
first attempt was somewhat of an expensive failure. I read through
the orchid archives on this question, but I could use some more
specifec answers.

  1. What is a good resist to use? I used asphaltum, and it didn’t
    hold up perfectly to the acid.

  2. Is it better to use aqua regia concentrated, or diluted with
    water (if so, what ratio?)

  3. Should I use a magnetic stirrer and float the piece upside down
    in the etching bath, or is there another method?

  4. Should I add heat (if using the magnetic stirrer)?

Thank you SO MUCH,
Wendy