I don't have a split back frame yet but am itching to try out some van dyke printing. Any suggestions as to what I can quickly rig up until I get a proper frame?
i don't have a big enough split-back frame for 8x10 paper so I use a paterson 8x10 contact proofer and used timed test strips to figure out exposure instead of exposure by inspection (for cyanotypes anyway...)
If you can tape you negative to the printing paper by one edge, then you can simply place them under a heavy piece of glass. You will be able to lift the negative to examine exposure progress without losing registration.