Re: Mottling in lighter tones in cyanotype?

[Alberto Novo <alt.list@albertonovo.it>]

> I switch to Platine because Crane's and COT 320 were staining in
> highlights...
> 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. 
Alberto