Free planter mold maker
Design a printable mold for casting concrete, cement or Jesmonite planters and pots in your browser, preview it in 3D, and download a print-ready STL or 3MF in seconds. Outer formwork plus an inner core for a clean hollow cavity - no card and no software to install. Try it without signing in; a free account gets you the files.
Free · opens the Vase & planter mold, an outer mold plus an inner core · STL & 3MF download
How it works
- Pick a pot or planter profile, or upload your own shape - cylinders, tapers, bowls and faceted pots all work.
- Set the outside size and wall thickness in true millimetres; the generator builds outer formwork plus an inner core so the cast comes out hollow.
- Preview on a virtual print bed, download the STL or 3MF, then cast your concrete, cement or Jesmonite in the gap between the walls.
What you get
A print-ready formwork set sized in real millimetres: an outer mold and a matching inner core that together leave a clean-walled hollow planter. The generator prints the pieces to cast a flexible silicone mold, so you can pour planter after planter and demold without cracking the concrete. Your model is only used to build your mold.
Materials & casting tips
- Mix: a fine sand-free concrete, cement-all or Jesmonite gives smooth walls and captures printed detail. Tap or vibrate the mold to release trapped air.
- Drainage: add a small dowel or bolt in the base of the core to leave a drainage hole, or drill one after the piece cures.
- Release: a silicone mold releases concrete cleanly; if casting against a printed mold directly, use a spray release and a little draft.
- Sealing: seal finished concrete planters with a masonry sealer if you plan to plant directly in them, to protect roots and prevent efflorescence.
- Filament: PETG holds up best to repeated wet casts; PLA is fine for the printed masters you cast silicone from.
Who it's for
Makers casting concrete and Jesmonite planters, pots and vases to sell or gift, who want a custom shape without CAD. For solid pieces like coasters and trays, see the concrete mold maker.
FAQ
Is the planter mold maker free?
Yes. Designing and downloading a planter mold is free, in a browser tab with nothing to install. Designing and previewing need no sign-in; downloading needs a free account.
How do I get a hollow planter, not a solid block?
The generator builds an inner core as well as the outer formwork. Concrete fills the gap between them, so the cast comes out hollow with an even wall. You set the wall thickness in millimetres.
Can I add a drainage hole?
Yes. Set a small dowel or bolt into the base of the core before pouring to leave a drainage hole, or drill one with a masonry bit once the planter has cured.
What file format do I get?
A standard STL or 3MF that loads straight into any slicer - Cura, PrusaSlicer, OrcaSlicer and others.