Epoxy resins are known to yellow when exposed to ultraviolet rays for a prolonged period of time. Liquid Art Ultra UV contains advanced hindered amine light stabilizers to ensure that your coating resists ultraviolet degradation. Liquid Art Ultra UV outperforms nearly all competitors products that we have tested when exposed to ultraviolet rays for a prolonged period of time. Liquid Art does contain UV inhibitors, but Ultra UV outperforms it significantly. If you are concerned that the project you coat with epoxy resin will come in contact with UV rays, we highly recommend using Ultra UV. Liquid Art Elite is a modified version of the other two products with improved clarity, durability, temperature resistance, a longer working time, as well as a lowered viscosity making it thinner.