Actually I was being very precise. What I said about brown and yellow/green stain was made in the context of their UV trannsmission with specific developers, which I have tested. Note that I did not say that "brown stain" is a more effective filter for UV light than "yellow/green stain", but that "the brown stain of Pyrocat-HD" is a more effective filter for UV light than "the yellow/green stain of the pyrogallol based PMK and Rollo Pyro." The use of the definite article "the" in this sentences limits the scope of the comparision to the specific items identified.
Originally Posted by Kirk Keyes