Epoxy by nature is not UV protected and is not meant to be used outdoors, if used outdoors, it can yellow over time in direct sunlight and may delaminate over time. We have customers that have used it outdoors with indirect sunlight and they report back that works fine. Also, extreme temperatures can effect the epoxy as it is a plastic when it hardens so it is possible that it can warp or crack in extreme heat or cold climates. You can put a high-gloss UV Urethane or Varnish over the top of the epoxy once it is cured. We recommend spraying it on as it takes an artist’s touch to put it on smooth with a brush. We do not recommend one specific product over another as our epoxy is meant to be a standalone product. This information is solely for you to "use at your own risk" meaning we have not tested every product on the market to know how well they will work together with our epoxy.