Cyanotype over pt/pd

Hello All, Was hoping for some help on this. I've made some cyanotype over pt/pd prints this evening and have run into yellow highlight staining. The paper isn't washing back to white in the highlights. This is unlike what happened with a straight cyanotype test, which cleared back to paper white. What could be the cause of this? Is there a remedy or any way of avoiding this in future?

Cheers,
Gareth

I've never done cyanotype over pt/pd before. I'd like to see what it looks like... My first thought is maybe there's a reaction between what is left from the pd/pt printing and the cyanotype chemicals. Looking up some old threads, it looks like there could be some reaction. But FAC is really soluble in water, so I don't know what it would stick to the paper like that. Is it completely staining and not washing out at all? (I'm looking at this: (there was a url link here which no longer exists) which may or may not help out all that much)

check with scootermm (Matt) here on APUG, he has some that worked very well - see them here