How hard is it to cast resin? It depends on you. It is an education process. No one can tell you to buy a certain product and that's the answer. You need to do some research and go to the sites of resin suppliers such as Alumilite and Smooth On and read their tutorials and than buy a product and experiment and continue to learn. I, like a majority per a post on this website a year or so ago who do casting for a profit,, use Smooth on products.