Quote Originally Posted by eggshell
Do any of these papers need pre-treatment before using for ziatype?

Socorro, Platinotype, Cranes Kid, & Cot320. Recommendation appreciated too.

Those will all work. Some people treat Socorro with Oxalic acid for DOP palladium. And I don't think COT 320 is similar to Platinotype but is instead very similar to Arches Platine.

Don Bryant