Maybe it's the water? I mix the silver nitrate with distilled water, but just
use tap water for the other two solutions. Lots of iron in the water in
Kalamazoo. Maybe it helps. Other VDB printers around these parts report
similar experiences with the aged solutions printing better.
I'm printing this week with a solution mixed 14 months ago and getting fine
results without any problems. I've stored the solution in an amber glass
bottle in a closed cupboard for this time.
Of course my experience with casein bichromate also runs counter to Sams'.
Wish I could get a handle on that process as he has. :)
Joe