I agree Bill, infact to substitute PPD in permanent hair colour does not mean absence o diamines. I’ve been trying with 2.5 PTD with pretty good results but the way to a complete range of effective
I’m still not clear on the issue about Betaines. Did some research and came across the above article. Don’t agree with everything it says either pro or con….but
What do you think? What could be a valid alternative to Betaines if needed?