Thanks Thomas and Kerik.
K, I'm using the old school A/B cyano mixture. Nothin special between coats. The cyano layers are needing about 2x the exposure time as the base pt/pd layers though.
Just developing in water bath and wash.
nelson, I just use a light table and some "safe release" scotch tape.
Rives BFK is VERY stable and retains almost its exact size for reregistering after the pt/pd print has been made.
I often have to "steam" my other mainstay paper (fabriano artistico) but Rives BFK doesnt need any of that. I've done a bunch of gum over pt/pd prints and even after 3 layers of gum printing on top of the pt/pd print, there usually isn't much issue getting the registration close enough.
I'm NOT using anything fancy to register, no condit pins or the like. Just a light table and visually lining them up.