"I work a lot and I think a lot. I really want to try to paint on glass. .Please will you ask him [mr. architect Taut ] if there are any transparent colors, which one can use to paint on the glass directly.. .I want to dispose of a new technique in which the artist can paint on the glass directly instead of canvas. When one wants to reach colors spiritually-bright, then a time will come that oil-paint and canvas are no longer suitable.. .So, if you have time, please ask Mr. Taut if he understands my view and maybe he knows the ways how I can follow my direction. (translation from German, Fons Heijnsbroek, 2018)"