Hey don, i'm not much of an expert on this topic, but this,http://www.youtube.com/watch?v=FSK8l-sAqy4
and maybe thishttp://www.thefind.com/crafts/info-sumi-ink-stick
might be of help to you.
The ink sticks are made from the soot produced by burning certain kinds of pine trees, at the time of year when the humidity levels are right, and then combining this soot with 'nikawa', a binder made from animal bones. More specifically, nikawa is made from the skins, bones, tendons and intestines of animals or fish skins and bones, which are boiled in water to extract gelatin. Excess water is evaporated away, and after cooling leaves a jelly-like glue. Nikawa does not dissolve in cold water, but can be dissolved when heated.
Here's a source for nikawa:http://store.hiromipaper.com/nikawacowskinglue.aspx
This mixture of the soot and nikawa, once properly combined (a physically-demanding job, from all accounts), is then placed in molds to dry, later wrapped in straw and aged, and, with the higher-quality products, the hardened ink blank is polished with shell to give it a high lustre.
Hope that helps.