Our favorite tip has to do with the way [Eric] makes this a reusable two-part mold, which is more akin to injection molding. To pour silicone for the second part and get it to separately nicely ...

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