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, etc.XL Gels shelf life is many times that of dry liver of sulphur. XL Gel is non-flammable. Real liver of sulphur in premixed gel form that is not only much easier to work with, but is it is specially formulated to have an extended shelf life (many times that of regular liver of sulphur). It is ready to use after a quick stir. You can heat it up for 15 seconds in a microwave to lessen viscosity if it is too cold to stir (be careful though it will be very hot). XL Gel can be brushed on. It is thick enough not to run. It imparts a patina on silver, copper, bronze and more. To make a dark patina solution, just mix one teaspoon of XL Gel in 12 oz. of heated water (around 140deg F). Use lower temperature water to make light patina solution