U of S | Mailing List Archive | alt-photo-process-l | Re: Mottling in lighter tones in cyanotype?

Re: Mottling in lighter tones in cyanotype?

I switch to Platine because Crane's and COT 320 were staining in

My problem with Crane's platinotype (which I still have) and then
Crane's Weston Diploma was staining in highlights and galloping
runoff - compared to where I am now with Arches Platine.
Not against the mottling (it might depend on the internal sizing of Plaine), but against bleeding and staining: try increasing the amount of k ferri, for example using a 1A:1.25B ratio or more (or less than 0.8A to 1B). You will also have a little more contrast and longer exposure times.