You can see the video below. The three methods are either printing silicone directly, printing a mold, casting silicone, or using high-performance elastomers, which are very silicone-like.

This tutorial on how to cast metal parts from 3D printed silicone molds is a perfect ... and durable metal part at home. After 3D printing a mold design using an Ultimaker 2 [Matt Borgatti ...