Quote Originally Posted by philldresser

I must say I have been underwhelmed by the Arches Aquarelle with the Kallitypes and the Saltprints.

You mention an acid presoak, and I assume that the size or paper base is alkaline. If so , would that have an impact on the cyanotypes as well.
I will try a 3% citric acid pre-soak (I have a lot made up) and see if it makes a difference.

I have read your kallitype article many times and will try the sodium citrate when I can get hold of it.

Thanks to all for the comments


Arches Aquarelle definitely appears to have an alkaline pH. An acid soak should improve its performance quite a bit with kallitype, or for that matter with Pt./Pd. I have not tried it with cyanotype, but all of the iron processes seem to like a slightly acidic paper.

Don't soak for too long, however, as the acid soak may break down the size, which result in a grainer, more textured look. But the size on Aquarelle is pretty tough, so maybe this won't happen.