Our high-quality coasters silicone molds in 8 different designs are perfect for filling with resin, Hydroflow, concrete or similar. There are no limits to your design. The following shapes are available: Square Circle Circle with wavy edge Geode To increase the durability of the molds, do not use sharp objects or excessive heat. Also, please do not store the molds upside down, otherwise the bottom will bulge upwards. Before use, wash out only with clean water and, if necessary, remove any dust or dirt particles with adhesive tape.