Re: Grainy Kallitype
I can't speak for kallitype, but I have had this problem with cyanotype and postulated it to be caused by too much solution used so that in the valleys of the paper bumps there would be more solution pooled that would then expose darker, probably because, as you say, there is more "humidity" there in the increased solution as well as more solution to actually GET dark. I finally discovered this as a possible answer when I was coating a bunch of test strips for test wedges, side by side, same piece of paper, same time drying and exposing and all else the same and the one strip which I had coated more thickly due to using up solution was incredibly grainy. This would explain to me why sometimes I got grain and sometimes I did not when nothing else varied. I think humidity plays a huge part in a lot of these processes....not just that a thicker cyano solution gets darker blue and such. But, unfortunately, no proof, just an hypothesis.
----- Original Message ----- From: dan jones
Sent: Monday, June 02, 2008 9:09 AM
Subject: Grainy Kallitype
I have just started working with the process and have had a reasonable amount of success so far. Today my prints started to get a very pronounced grain pattern. the grain appeared with both digital and camera negatives.
Could this be related to humidity/dryness of the coated papers? Or could it be a chemical (ferric oxalate) problem? No change in paper (stonhenge) or developer (sodium citrate). Coated papers are air dried with a fan, no heat applied.