Coat all inside areas of the mold with a thin layer of petroleum jelly to prevent the resin from sticking.
Attach the two halves of the mold using the clips provided, clothespins or rubber bands. Skip this step with a one-part mold.
Combine the needed amount of resin in a bucket with the catalyst. Different brands of resin have different ratios, so follow the mixing instructions carefully to ensure that the resin will cure correctly. Mix well using a stir stick or other tool.
Pour the poly resin mixture into the mold and allow it to harden for four to six hours. Smaller figurines require less time to cure, and larger molds require more time.
Remove the clips, if using a two-part mold. Peel back one side of the mold at a time and remove the figurine. Wash the mold with grease-cutting soap such as dish detergent.