I had mixed citric acid into the sensitizer at the time of application as Mike Ware advised. I tried your advice of pre-coating the paper instead. That stopped the speckling issue. Thank you.

I'm still not getting a lot of adhesion though. There is a lot of wash-off of Prussian Blue in the wash. This results in shadows that are not very dark. And, H2O2 seems to have no effect at immediately restoring some density (like it does with original cyanotype).

Well, I bought some Arches Bright White Hot Press and Bright White Cold Press to experiment. That's all they had at the local art store. Both have gelatin sizing. Maybe I'll have to sport for the Weston Diploma Parchment.

Any other tips are appreciated. Once I have these issues solved, I can start toning and tweaking from there.