I have been refining my cyanotype technique and am having a problem. I bleach the image with Sodium Carbonate and then redevelop in Gallic Acid. The image looks great until it starts to dry. Then it is obvious that the 'ink'/color is bleeding into neighboring fibers destroying contrast, sharpness, etc. I also get light spots which mottle the entire image. I don't have this problem when I tone with Tannic Acid.

I tried an acid final bath. I also tried an alkaline final bath. No dice.

I really like the color of the Gallic Acid. But, I need to solve this problem. Ideas?

I am using Arches Aquarelle Bright White paper, 140lb.

Thanks for any tips