Liver of Sulphur XL Gel is formulated for extended shelf life, versatility & convenience. XL Gel is used to patina metals such as silver, copper, bronze. XL Gels shelf life is many times that of dry liver of sulphur. XL Gel is non-flammable. Newly designed squeeze bottle for easy dispensing. Shake XL Gel before use for consistent results. May be microwaved for no longer than 15 seconds. (WARNING: CONTENTS WILL BE HOT!)