How often is the first print of a session a final version? If it's a test print anyway, a little staining usually isn't important.
Right David. That applies to all developers IMO. Make sure the chemistry is all settled out, run two or three prints to make sure, or two or three blank pieces of paper.
My point is that I've seen the pink stain sporadically with what's probably the best amidol that can be obtained. I wonder what it was like in years past when amidol was produced by more sources and in much larger quantities?
Here's the kicker question: Did Weston have this problem? :p (no debate initiation intended :D).
I don't want to continue, as that would get me accused of 'advertizing', so this is merely an explanation of my answer and I'll leave it at that.
Chemical analyses of this sort start by giving the theoretical % of C, H, O, N, S etc, and then the actual values present.
Thus: Calc for C10H14N2O: C, 67.38; H, 7.92. Found C, 66.62; H, 7.66. And etc.... The error in ratios of C, H, N and O in this type of representation will tell you how much amidol there is and how much is organic and metallic junk. (this example is not Amidol, it is hypothetical taken from an off the shelf text)
The analysis as given in the reference is not revealing in any way.