Ewesly / Holographic Formulae / Jeff Blyth's Copper Sulphate
35 g Copper Sulfate
10 ml Acetic Acid
110 g Potassium Bromide
One litre water
Bleaching time: One and a half times the time it takes to clear.
Temperature: 20C Agitation: Intermittent
One of the best "Cures for PBQ". Identical results to the PBQ, less costly than Fe EDTA. Unfortunately the original article did not disclose the strength of the Acetic Acid, whether it should be Glacial or 28%. It seems to work fine with the 28%.
Shelf life: Pleasant blue-green color when mixed, dirty green when exhausted. Not prone to oxidation like PBQ.
Source: Jeff Blythe, "A Novel Approach to Colour Processing", <a href="JBCuSO4Wvfrnt.pdf" title="The first Copper Suphate Recipe I had ever seen" target="_new">Wavefront Volume 2 Number 3, p.23 (1987)</a>