There ar five grades: Standard (Yellow/Grey), Terracotta, Silver Grey, Black and Superfine White. Each grade is presented in similar packs containing 2 x 56•7gm. sticks and the general instructions for preparation and usage are the same. Once equal quantities of each stick have been mixed the resultant putty is at first soft and highly adhesive and then gradually hardens. Speed of hardening is dependant on temperature and at normal temperatures (20-25 deg C) Milliput becomes rock hard in three to four hours. By the application of heat the setting time can be reduced. Danger! H315 Causes skin irritation H317 May cause an allergic skin reaction H319 Causes serious eye irritation