Negative Technique Welcome › Forums › Product Questions › Negative Technique Tagged: essay, writing This topic has 2 replies, 3 voices, and was last updated 2 years, 7 months ago by Rene. Viewing 2 reply threads Author Posts 17th May 2021 at 9:55 am #21192 reneParticipant Hello, for the negative technique I use a powder given me by a friend in China. I dissolve this powder in hot water. Does anybody nows which chemical is this powder? René rene@rene-boell.de 20th August 2021 at 7:46 pm #21292 Tetsu UmaParticipant Is it possibly peach sap or alum? 20th August 2021 at 10:11 pm #21296 ReneParticipant Yes, I think alum is correct, I will try the peach sap. Author Posts Viewing 2 reply threads You must be logged in to reply to this topic. Login or Register with email, Facebook, Google or LinkedIn account