Important: A patch test is required at least 48 hours prior to treatment. The test involves putting a tiny amount of the mixed dye onto the skin, either on the inside of the elbow or out of sight behind the ear. This is to ensure that you are not allergic to any of the ingredients used in the products. If you have had a patch test at another salon you will still need a repeat test, as different brands may cause different reactions. Please call to arrange a patch test or why not have another treatment and have a test before you leave?