I am planning to create 4 tiles that each contain an aluminum Porsche paper weight. The tiles are to be included in the poured concrete threshold of my garage as a sort of ‘Easter egg. They will be exposed to direct sunlight, weather and cars driving over them. The dimensions of the paperweights: 4″ L X 1’ H X 3/4″ D. I plan to use rectangle molds. What is the best/hardest clear resin for this project (or other appropriate material)? Thanks.