The approach I took to sorting this all out was a series of planned tests. I spent several weeks prepping in my own studio. Each experiment was designed to reveal a different variable in this complex technique. In all I prepared over 200 samples! This obsessiveness was possible because I was able to solicit donations of 18 unique formulas of stain from 4 manufactures in 3 countries! I would like to acknowledge the generous contributions of Cliff Oster and Reusche Co (USA), Debitus (France), and Derix Glasstudios (GERMANY) for stains from Keracolour. Please look on the manufacturer's page for a contact list for these companies.