Pour the necessary quantity (maximum 30g) of bleaching powder into a glass orplastic bowl. Mix with the cream peroxide with a 1:2 ratio, e.g. for 25g of bleaching powder, add 50ml of cream peroxide 10/20/30/40* vol. (*40 vol. may be used for freehand techniques). Leave for a maximum of 60 minutes (if using low volume cream peroxide).