[CreatuveHands]

Thank you so much Julieta,  very good information for me.  Very nice explanation. A Very less information have available  in online . 
Do you know the formulation to make 20 vol and 40 vol ?. Will you share some idea with me about making of this kind developer?. 
Also do you know about hair dye cream formulation?. 
Waiting for your reply.