All of my current tissue is made with so-called pure pigments from
the Color Craft Company of Hartford, CT. These pigments are available in
4 and 8 oz bottles and are much more economical than the small watercolor
tubes. I have also obtained numerous pigment samples from companes like
Dupont, Heubach, Cib-Geigy, etc.
The majority of pigments work fine with carbon printing, but some
cause staining and fog, others will not disperse well in the gelatin
solution, while others destroy the bond that holds the pigmented
gelatin image on the final carrier. I weigh to .1g the amount of
pigment per 1000ml of solution, and keep good ntoes. If it works,
great, otherwise chalk it up to experience and move on.
As for dispersions, nothing special. I use 35g of sugar per 1000ml of
gelatin solution, and 10-15ml of glycerine. I first grind everything
up very carefully with a pestle and mortar, then mix in a blender at
medium speed for 2-3 minutes. This kicks up a lot of air bubbles and
you must wait for 2-3 hours to coat, but gives wonderful dispesion.
A friend of mine tried the blender and swore that it did not work, that
the bubbles would never go away. But it works fine for me.
Sandy King