What material to make a resin mold with?

Hey all, I want to experiment with making my own resin molds, and I’m wondering what material to print it from? I’m not familiar with all the new varieties of flexible filament there are out there, but man are they sure expensive!

I’ve been looking at TPU (and so looking at modifying my Ender 3v2 from bowden to direct), but is that the best material to use? What’s the difference between all the different flexible filaments? How can I tell from the description if it’s the kind that I need for this project?


For flexible’s, there is the Flexible PLA filament which shouldn’t need your printer converted. Can’t say if it will suit your needs.

I am assuming you are using epoxy or polyester resins?

Flexables might work but the layer lines will grad and not necessarily release. You will still need a mold release no matter.

It is possible that PLA with a release and just sacrifice the mold may work too. Rather than have the part pop out just tear the mold away. Just a thought.

Yeah I’d like to use epoxy resins.

I have no problem needing to use a mold release if needed, and I was hoping to make molds that I can reuse, not just one offs.

That is fair. I have used a lot of epoxy molds but almost always vulcanised rubber mold.

You can try and if you use a lot of release or even wax to fill in layer lines it could work really well. You will need to worry about the heat epoxy generates, melting the mold, and bonding. if you can smooth off all the layer lines I see no real issue.

My molds often had undercuts but I could easily stretch the mold around the parts.

I tried to print a long open top round ice mold and it refused to release.