Copper Etching - Edinburgh Etch

G’day Karla; I read the essay in the URL
Edinburgh Etch, Keith Howard, Beguin And note
that anhydrous citric acid is specified as an addition to ferric
chloride etchant for copper, etc… In MY OPINION I see no reason why
the citric acid should be anhydrous. There is a monohydrate of citric
acid, and this is most probably the citric acid which is found in the
supermarkets, and I don’t think the fact that it may not be anhydrous
would not matter all that much After all you are going to add it to
a water solution anyway. It seems to me that the object of adding
citric acid is to lower the pH and add a few more hydrogen ions. I
would try a little and see. Citric acid is very cheap.

To be honest, I wasn’t keen on the style of that writer - it seemed a
bit on the pompous side (academic?) I suspect it was translated or
written by a German.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ