You need real plastic parts to test. Not 3D printed parts, but parts made in the plastic you plan to sell. The catch is that a metal mold can cost thousands of dollars and take weeks to build. So can you just print the mold instead?
Yes, you can use 3D printed molds for injection molding. But they work for a short run, not a long one. A steel mold can make a million parts or more. A printed mold may only make dozens or a few hundred.
For many projects, that’s all you need. It makes a printed mold a smart way to test a design before you pay for metal tooling.
In this guide, we cover how a printed mold works and how many parts it can make. We compare its cost with aluminum and steel molds. We also cover which plastics work best and when it’s time to move to a metal mold.
Yes, you can use 3D printed molds for injection molding, but only for small runs. A printed mold is made from a stiff, heat-resistant resin instead of machined steel or aluminum. It can be ready in days and costs far less to build. The trade-off is mold life.
Most printed resin molds make about 50 to 200 parts. Some fail in under 10 shots, while others last into the thousands. It depends on the plastic, the part shape, and how the mold is run. Printed molds can also show layer lines, and they don’t hold tolerances as well as metal.
That makes them a good fit for testing a design, checking fit, or making a small batch. For thousands of parts, an aluminum or steel mold costs less per part. In the industry, using printed molds this way is one form of rapid tooling.
A printed mold runs on a real injection molding press. It isn’t a shortcut or a hack. The big changes are what the mold is made of and how gently it gets run.
Here’s how the process works:
Because the part is truly molded, you can test how it fits, flexes, and holds up. We can use our in-house printers to print small molds for short runs like this.
Knowing how the mold works raises the next question: how long will it hold up? A printed resin mold can last anywhere from a few shots to a few thousand. In practice, 50 to 200 parts per mold is more common. In our own shop, fine detail on a printed mold starts to fade within about 100 soft-plastic shots. Sometimes it fades after just a handful.
Where your mold lands in that range depends on how hard each shot is on it. These things wear a printed mold out fastest:
You can usually see a printed mold start to fail before it breaks. Watch for surface detail that fades or roughens. Also look for cracks and parts that drift out of size.
| Mold type | Typical shot life | Best for |
| Printed resin | A few to a few thousand (50 to 200 is common) | Design tests and fit checks |
| Aluminum | Thousands to about 100,000 | Prototypes and low-volume production |
| Steel | 100,000 to 1,000,000+ | High-volume production |
For steel, the industry uses SPI mold classes. A Class 101 mold is built to run 1 million cycles or more.
Printed metal is a different story. Inserts printed in tool steel can last about as long as machined steel. They’re often used to add cooling channels to production molds, not to save money on a test run.
For a closer look at metal mold life, see our guide on how long injection molds last.
Shot life is half the story. The other half is what each part costs. A printed mold costs far less up front than a metal one. But the mold’s price isn’t the whole bill.
One printer maker puts the material for a printed injection mold at about $25 to $200, depending on size. Aluminum molds often cost about $2,000 to $15,000. Production steel molds often run $10,000 to $100,000 or more.
The number that matters most is cost per part. Say a printed mold uses $200 in material and makes 100 parts. That’s $2 per part for the mold alone. A $2,000 aluminum mold that makes 10,000 parts costs just $0.20 per part.
These costs still apply with a printed mold:
Still deciding whether to print your parts or mold them? See our cost breakdown of 3D printing vs. injection molding.
Each mold type fits a different stage of a project. Printed molds are fast and cheap, but they wear out quickly. Steel molds cost the most, but they can run a million parts or more. Aluminum sits in between.
| 3D printed mold | Aluminum mold | Steel mold | |
| Mold cost | Lowest; often under $200 in material | About $2,000 to $15,000 | About $10,000 to $100,000+ |
| Lead time | Days | About 1 to 4 weeks | About 2 to 8+ weeks, based on complexity |
| Shot life | A few to a few thousand | Thousands to about 100,000 | 100,000 to 1,000,000+ |
| Surface finish | Layer lines can show | Good | Best; mirror polish needs hardened steel |
| Tolerance | Looser | Tight | Tight |
| Best use | Design tests and fit checks | Prototypes and low-volume runs | High-volume production |
If a printed mold can’t do the job, aluminum takes over. Aluminum is the bridge between a printed mold and steel. It’s usually faster to machine than steel, and it can make thousands of good parts. For many projects, that means a quick aluminum mold first, then a hardened steel mold once the design is set.
Compare your options with our prototype and production molds.
The plastic you shoot into a printed mold has a big effect on how long the mold lasts. Plastics molded at lower temperatures are gentler on it. Hot or glass-filled plastics wear it out fast. The shot counts below come from printer makers’ own testing, so treat them as rough guides.
Good fit:
Use with care:
Expect very short mold life:
You may also wonder, “Can you injection mold with PLA?” PLA itself can be injection molded. But a mold printed in PLA is a bad idea. PLA starts to soften at about 130–150°F (55–65°C), so the mold would warp under hot plastic.
Not sure which plastic fits your part? Our material selection guide can help you compare options.
A printed mold is a tool for a specific job. It shines early in a project, when your design may still change. It falls short once you need volume, polish, or tight specs.
Use a printed mold when you need to:
Skip it when your part needs:
We’re an injection molder and mold maker in North Logan, Utah. We work with businesses across Cache Valley, Northern Utah, and Southern Idaho. Our team handles part review, mold design, machining, finishing, and mold trials under one roof.
We can 3D print small molds for short runs. A printed mold can be done in as little as a week. When your design is set, we can build an aluminum or hardened steel mold for production.
We sample and inspect every mold before production starts. Ready to talk about your project? Contact us or call (435) 774-9090 today!
