Just measure th pH of a working solution of Hypercat and you will ifind that it is well over pH 12, about 12.4 or so from my tests.
Of course, my measuring instruments could be wrong, but they appear to be working ok because when I measure the pH of other developers, PMK for example, my measurments of pH 9.5 to 9.7 turn out to be very close to to the 9.6 that Hutchings reports.
It is certain that the combination of even small amounts of sulfite and ascorbic will kill the stain with pyrocatechin developers, unlike pyrogallol types which are obviously more resistant. However, what I am suggesteing is that the pyrocatechin based developer will allow much more ascorbic and/or sulphite without losing the stain if it is working at a higher pH.
Originally Posted by jdef