Christopher Hickman wrote:
What's the best way to get small black and white stones for marking Koans?
If you're willing to order online, try: http://megaglass.com/opaqueflats.htmlI can't vouch for the opaques, but I recently ordered a bunch of transparent glass flats from them, and I was happy with the quality.
The 18-22mm stones might be a tiny bit bigger than the ones that came in the Zendo box, but they should work fine.
-- Kory Heath http://www.koryheath.com