Ferric nitrate etching solutions turned purple

was: Fairly intricate design to etch

Hi Noel,

I wonder why your ferric nitrate turned purple when you added citric
acid? When I did that, it did not turn purple, and it did seem to
extend the life of the etching solution.

I will add that it also works with the saltwater etching
solutions----the copper precipitates out of the solution, and it
lasts much longer.

Cynthia Eid