Although its true that you double coat in the process I refer to - I refer to instead coating once, exposure, development - recoating, register neg again, expose again, develop again.
Hence the requirement for the paper to be stabilized in terms of expansion/shrinkage between exposures - it could refer to many similar processes I guess, tri-color gum and gum-overs being examples.
Anyone done double coat/ double exposure / double development ?
My reply to the cost of Pt is half-hearted (I'm poor!) - but I could try this on for size: after all the work you've done in the imaging process, why wouldn't you want to optimise the output ? If you truly beleive in Pt/Pd enough to do it in the first place, then why not push for that extra dmax and therefore extra range (if done correctly). It's not the only cost in the process - maybe your paper, film, lovely oldlenses, subject and patience deserve it ?