boyooso and chrobry
I have done some pt/pd and some van dyke browns on japanese gampi paper.
Through my experience (havent tried sizing the tissue) Ive noticed that I double the amount of chemistry I use to coat them.
My working procedure, if memory serves, is this:
I measure out the chemistry, say 1.5ml for an 8x10 sized print (usually Id use .8ml for an 8x10)
Ill put a piece of paper underneath the tissue, say some cranes 90# cover... then quickly pour and coat the tissue with a brush, Ive found brushes like the richeson 9010 work best. The solution will soak through and get on the base sheet some, but if Im fast enough I can get the tissue coated adequately.
when I processed the coated and exposed sheet I found using a piece of clear plexiglass and some magnets to adhere the print too helped a great deal, this kept me from having to touch the tissue during the whole process. As touching it in the slightest manner seemed to tear it, especially on sheets as big as 8x10.