Quote Originally Posted by philsweeney
I replenish per sandy king's article on kallitypes. I keep a second bottle with the appropriate amount of dichromate in it for topping off.

I want to try the cot-320. Does it need an oxalic acid bath for kallitype? Unfortunately I had no luck with the stonehenge rising, maybe I got a funky batch? I also had no luck with the artistico. Crane's platinotype is OK with no oxalic acid but I find the paper too delicate and I have to handle it very gently.
So if you wanted to print negatives with different DR you would have to maintain 2 bottles for each dilution, which seems very tedious.

The COT 320 doesn't require any pre-treatment. I've used it with several different processes (VDB, cyanotype, palladium/platinum DOP, and ziatypes) with good results. It does have signifigant dry down.

What kind of problem did you have with Stonehenge? I've also got some Lenox ordered, it would be nice to have a good inexpensive paper.

Platinotype is an okay paper but it does tend to tear when handling large wet sheets.