Re: Tween 20, mottling and grain

Terry King (101522.2625@compuserve.com)
Wed, 19 Feb 1997 05:58:49 -0500

Dick sullivan wrote:

>. If you coat too heavy, in pursuit of
>the HGOD, then coating problems arise. Mottling is one of them, I see it
a>ll the time in beginners prints and even in advance workers prints as
well.

Whether you are using cyanotype, kallitype or platinum too much solution
leads to puddling and uneven finishes. The simple solution is to size the
paper first. That way a single coat will give you good gradation, even
covering and HGOD through effective and safe self masking..

> Even with the traditional developing
>out platinum, the yellow of the ferric oxalate prevents a very deep
>exposure of the emulsion. Again any wash off reveals the paper base.

I have never had this happen. And my ferric oxalate is a beautiful green.

>. During coating the brush scrapes the
>surface of the paper and raises up paper fibers.

A gentle brush gently used should avoid this but I tend to avoid papers
with such over sensitive surfaces.

Terry King