File guidelines

Getting your file print-ready.

Most files print fine as-is. These are the things that trip people up — skim them, or just upload and let the quote tool flag anything.

Accepted formats

  • STL — the universal mesh format. Great for finished models. No units baked in, so double-check the size in the preview.
  • 3MF — mesh plus units, and it carries painted colour regions for multi-colour prints. Preferred when you have it.
  • STEP / STP — solid CAD. Send this if you have it; it’s exact. The server meshes it for the preview and price.

Max file size is about 100 MB.

Units & scale

We print in millimetres. STL has no unit information, so a model exported in inches comes in 25× too small. After uploading, check the dimensions shown on the preview — if they’re wrong, re-export in mm.

Watertight meshes

The model should be a closed, manifold solid — no holes, no flipped or overlapping faces, no stray shells. Most CAD exports are fine; sculpted or scanned meshes sometimes need a repair pass (Meshmixer, Blender, or Microsoft 3D Builder all do it). If a file won’t slice, this is usually why.

Wall thickness & small features

  • Keep walls at least 0.8 mm (two perimeters at a 0.4 mm nozzle). Thinner and they get skipped or come out fragile.
  • Embossed or engraved text: at least 0.8 mm wide strokes and 0.4 mm deep/raised.
  • Pins and posts under ~2 mm diameter are delicate — thicken them or expect them to be fragile.

Tolerances & fit

FDM holds roughly ±0.3 mm on a typical part. Design clearance into anything that has to fit together — about 0.2–0.4 mm of gap for a sliding fit, more for a loose one. Holes print slightly undersize; oversize them by ~0.1–0.2 mm or plan to ream them.

Orientation & supports

We orient the part for strength and surface finish unless you tell us otherwise — for a 3MF we replay the rotation you set in the preview. Don’t add supports yourself. Support is opt-in and priced separately; leave it off the model.

Multi-colour

Upload a 3MF with painted colour regions. Multi-colour prints are PLA only, and priced as PLA regardless of the material picked. A single-colour part in any material just uses the colour dropdown where one is offered.

When in doubt, upload it — the tool previews the real dimensions, checks it fits the build volume, and prices it. Nothing is ordered until you choose to.