◆ Concrete

Faceted concrete planter mold

A low-poly geometric planter, 110 mm across and 90 mm tall, to cast in concrete. A silicone mold kit from printed parts.

Make your own silicone mold
3D render of the faceted geometric planter master fused on its printed charcoal base, between the orange and blue round walls, with the charcoal clamps behind
Concrete ~465 g Pro early access

A faceted geometric planter 110 mm across the widest facets and 90 mm tall: three hexagons, the middle one turned half a step and set wider, joined by 24 triangular facets that catch the light the way the classic low-poly concrete pots do. The well is a hexagon lined up with the rim, 8 mm in from it, over an 11 mm floor with a 10 mm drainage hole through the middle.

Read more

Made with the box mode of our silicone mold maker in its round shape, which the tool itself suggests for this low, wide pot. Print the base with the planter fused onto it, the two walls and the two clamps, and pour about 1310 ml of silicone. It fills the well as it rises and becomes a core, with a pin on its tip that forms the drainage hole, so every cast comes out hollow and drained with no insert.

The belly is wider than the foot, so the cured block gets one straight slit down its side to let each planter out, and the printed walls hold it shut for the next pour. Cast it in grey concrete, white Jesmonite or a terrazzo mix. The zip carries every printed part, the planter master as its own STL, the tool's own print-settings sheet and a recipe file for the generator.

Shown as a 3D render of the printed mold parts pulled apart around the master, not a photo.

What you need

4
  • About 1400 ml of silicone (mix it in one batch)
  • Concrete, Jesmonite or a fine cement mix: each cast is 314 ml, about 691 g in concrete
  • A sharp craft knife for the slit, and tape for the wall seams
  • Fine sandpaper, a concrete sealer and felt pads

How to cast it

7

  1. Print the base with the master fused onto it, the two walls and the two clamps.

  2. Stand the base on the table. Set each wall down a few centimetres out from it and slide it in over the table until the ridge round the base sits in the groove at its foot, then slide the clamps down over the seams. Once they are on, the walls cannot lift, and the ridge seals the bottom.

  3. Mix 1400 ml of silicone in one batch and pour it in a thin stream down the inside of a wall, letting it rise round the master and into its well until it covers the top.

  4. Once it has cured, take the clamps off and slide the walls straight out. The planter is wider higher up than at its foot, so cut one straight slit down the side of the block with a sharp knife, from the open face to about 10 mm short of the top, open it like a book and lift the master out.

  5. Turn the block over and stand it back inside the walls with the clamps on, which hold the slit shut. The opening is the foot of the planter, with the silicone core standing up in the middle and the drainage pin on its tip.

  6. Mix a fine concrete or Jesmonite a little wetter than for a slab, pour it slowly down one side of the ring round the core, and tap the walls for a minute to raise the air. Fill level with the opening and strike it flat, wiping the tip of the drainage pin clean.

  7. Leave it to cure for a day, take the walls off, open the slit, peel the silicone off the outside and twist the planter off the core. Sand the foot flat and seal it.

Print details

14 hPrint time
~465 gFilament
5Printed parts
138 × 138 × 128 mmSize (W x D x H)
All print details
Print details
Cast materialConcrete
Printed parts5
Size (W x D x H)138 x 138 x 128 mm
Print bed needed160 x 138 mm, 128 mm tall
Filament~465 g
Layer height0.2 mm
Infill15%
SupportsNot needed
DownloadZIP: 5 printed parts (STL) + planter master (STL) + print sheet + recipe
Added2026-09-26

Pro early access until October 26, 2026, then free with any account.

Like it or post your print on Thingiverse

Make your own silicone mold →

Made with the free Silicone mold maker generator. Upload your own model and get the same kind of mold built around it, in your browser.

Free for personal use. Selling the pieces you cast needs a commercial licence (Pro or Founder); passing on the file itself is not permitted on any plan. Full terms.

New to casting? Read the silicone mold maker guide.

geometric concrete planter moldfaceted planter moldlow poly pot moldcement planter moldsucculent pot moldsilicone concrete mold

Questions about this design

How do I get the faceted concrete planter out of the silicone block?

Through one slit. The belly is wider than the foot, so after the first cure cut a straight slit down one side of the block with a sharp knife, from the open face to about 10 mm short of the top, and open it like a book. Stand the block back in the printed walls with the clamps on and the slit closes tight for every pour after.

Does the faceted concrete planter have a drainage hole?

Yes, 10 mm across, through the middle of the floor. The silicone that fills the well forms a pin on the tip of the core, and the pin reaches the open face, so each cast comes out with its hole. Wipe the pin tip clean when you strike the foot flat, and plug the hole with a cork if the pot stands indoors without a saucer.

Which mix gives crisp facet edges on the faceted concrete planter?

A fine mix with no gravel: a rapid-set craft cement, a sand and cement mortar, or Jesmonite. Brush a thin first coat into the facet corners, pour the rest slowly down one side, and vibrate the walls for a full minute (an orbital sander held against them works). Coarse aggregate cannot fill the sharp corners and leaves them ragged.

More designs

See all concrete molds →