Can you 3D print silicone? What actually works
This guide was drafted with AI assistance.
Not on a normal home printer. Silicone never melts, so an FDM printer cannot extrude it, and ordinary resin printers cannot cure it. Flexible filament (TPU) is not silicone and is much firmer. A few professional options do print real silicone, but they are firm and expensive. What almost every maker does instead: 3D print a mold, then pour liquid silicone into it. You get real, soft, skin-safe silicone with any shape your printer can make.
Why a normal printer cannot print silicone
An FDM printer works by melting plastic, pushing it through a nozzle and letting it harden again. That only works with thermoplastics like PLA, PETG and TPU. Silicone rubber is a thermoset: two liquids react and cross-link into a solid, and once that has happened no amount of heat turns it back into a liquid. It burns before it melts.
You could in principle extrude uncured liquid silicone through a syringe, and people have built experimental paste printers to do it. But the liquid sags before it cures, so the shapes are crude, and none of this is a product you can buy and use.
Every option, compared
| Route | Real silicone? | Softest possible | Surface | What you need |
|---|---|---|---|---|
| Print a mold, pour silicone | Yes | Very soft (Shore 00-10 and softer) | As smooth as the mold or master | Any FDM printer, a silicone kit |
| Flexible filament (TPU/TPE) | No | Around Shore 60A to 85A | Layer lines | An FDM printer that handles flexibles |
| Silicone printing resin | Yes | Shore 40A | Smooth | A professional SLA printer |
| Industrial silicone printing service | Yes | Depends on the service | Good | A budget per part |
For anything soft, squishy or meant for skin contact, the first row is the only one that is both real silicone and affordable, which is why the rest of this page is mostly about it.
Flexible filament is not silicone
TPU and TPE filaments are the usual answer to "can I print something rubbery". They are good materials for bumpers, gaskets, watch straps and phone cases. But they differ from silicone in the ways that matter most for soft parts:
- Hardness. Common TPU is around Shore 95A, and the softest printable filaments sit around 60A to 85A. Soft casting silicone starts at Shore 00-10 and goes up to around 30A. A 60A filament feels like a firm eraser next to a 00-30 silicone.
- Surface. A printed part has layer lines and tiny gaps between them. They trap dirt and cannot be cleaned the way a smooth, non-porous silicone surface can.
- Material. Filaments are not sold as skin-safe for long contact the way platinum silicones like Ecoflex and Dragon Skin are.
Silicone resin: real, but firm
Formlabs sells Silicone 40A Resin for its Form 3 and Form 4 printers, and it is genuinely 100% silicone rather than a silicone-like acrylate. It is rated Shore 40A with 230% elongation, which makes it a strong choice for seals, grips and flexible prototypes.
Two things keep it from replacing casting: it needs a professional SLA printer, and 40A is much firmer than the silicones used for soft pieces (00-30 to 10A), which also stretch four to ten times their length. If you need something firm and you already own one of those printers, it is worth a look. Check its own documentation before planning skin contact.
Print the mold, pour the silicone
Get or design the shape as a 3D model
An STL of the part you want in silicone. Designed in Blender or Nomad Sculpt, or downloaded.
Turn it into a mold
Either print a rigid two-part mold and pour silicone straight in, or print the shape as a master and make a silicone mold of it in a printed shell. The second gives a smoother result. How to 3D print a mold for silicone casting compares both.
Pour platinum silicone
Mix a two-part platinum silicone 1:1, degas it if you can, pour, and let it cure for 3 to 16 hours depending on the grade. Ecoflex vs Dragon Skin helps you pick the hardness.
Demold and trim
Open the mold, trim the seam, wash off the release agent. The mold is reusable, so the next part is just another pour.
What people mean by "3D printed silicone mold"
The phrase is searched a lot and means two different things, so it is worth separating them:
| Meaning | What gets printed | What gets poured | Guide |
|---|---|---|---|
| A printed mold that makes silicone parts | The mold | Silicone, to make the part | Print a mold for silicone casting |
| A silicone mold made from a printed model | The model (master) and a housing | Silicone, to make the mold; then resin, wax, soap or plaster into it | Make a silicone mold from a 3D print |
Doing it with Meshcast
Meshcast turns an STL into a mold you can print, free and in your browser:
- Silicone mold maker, contoured mode: a printed shell that hugs your model at the silicone thickness you set, with clips and a pour funnel. The thin even gap uses far less silicone than a box.
- Box mode: the classic printed housing for a silicone block mold, with an estimate of how much silicone it takes.
- Two-part mold maker: rigid printed halves with alignment keys and a pour funnel, for pouring silicone (or wax, resin, soap) straight in.
- Silicone calculator: the volume, weight and cost of a mold from your object's size, before you buy a kit.
Common questions
Can you 3D print silicone?
Not on a normal home printer. Silicone rubber is a thermoset: it cures by a chemical reaction and never melts, so an FDM printer cannot extrude it. Professional SLA printers can print a silicone resin, and industrial services print liquid silicone, but for most makers the practical route is to 3D print a mold and pour two-part silicone into it.
Is TPU the same as silicone?
No. TPU and TPE are flexible thermoplastics, not silicone. Even the softest common filaments are far firmer than soft casting silicone, and a printed TPU part has layer lines that trap dirt and cannot be cleaned like a smooth cast silicone surface. TPU is great for bumpers, gaskets and phone cases, not as a substitute for skin-safe silicone.
What is a 3D printed silicone mold?
The phrase usually means one of two things: a mold you 3D print and pour silicone into to make a silicone part, or a silicone mold made around a 3D-printed master that you then cast resin, wax, plaster or more silicone into. Both use the printer for the rigid parts and pour the silicone as a liquid.
Can a resin printer print silicone?
Formlabs sells Silicone 40A Resin, a 100% silicone material for its Form 3 and Form 4 SLA printers, rated Shore 40A with 230% elongation. It is a real option for firm silicone parts like seals and grips. It is much firmer than the Shore 00-30 to 10A silicones used for soft cast pieces, and it does not run on other resin printers.
Made by meshcast.app. Not sure which route fits your part? Email us and we will tell you.