Tom
My approach is to it the other way round if I am seeking a
platinum/palladium/gum print, i e put down the gum colours first then size
and then make the platinum print on top. But my original comment was
related to the use of a size for pt/pd printing.
I was interested to see that you have confirmed my experience that yet
another way of controlling contrast given negs of different densities is to
use more gelatine with less dense negs. This also has an interesting
effect upon the colour of the image with browns for the platinum and blues
for palladium which produces very interesting 'split toned' effects.
Terry