---
title: "STL file: meaning in gemology"
description: "STL is a triangle-mesh format and the standard for 3D printing. Slicers such as PrusaSlicer, Cura and Chitubox read it."
url: https://digitalgemology.com/learn/glossary/stl-file
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

> Markdown copy of https://digitalgemology.com/learn/glossary/stl-file. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons.
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[Glossary](https://digitalgemology.com/learn/glossary) · Cutting and files

# STL file

Also called STL

STL is a triangle-mesh format and the standard for 3D printing. Slicers such as PrusaSlicer, Cura and Chitubox read it.

## In more detail

STL stores only the surface triangles, with no units. Jewelers print a stone in resin to test a setting before they cast metal.

## How we measure it

Our STL files are watertight, so they print and cast without repair. Our tools also read your own STL files.

## Related terms

- [Mesh](https://digitalgemology.com/learn/glossary/mesh): A mesh describes a 3D surface as many small flat triangles joined at their edges. STL, OBJ, FBX and GLB files store a mesh.
- [3D model](https://digitalgemology.com/learn/glossary/3d-model): A 3D model of a gemstone is a digital solid of its facets for CAD, rendering, printing or games. An exact model has flat facets, sharp edges and a closed, watertight surface at real size.
- [Watertight](https://digitalgemology.com/learn/glossary/watertight): A watertight model is a closed surface with no holes, so it encloses a solid. In a closed mesh, exactly two triangles share every edge.

## Learn more

- [Who uses our files](https://digitalgemology.com/about/files)
- [T73 Round Brilliant Cut](https://digitalgemology.com/cuts/t73-round-brilliant)
- [Your own file](https://digitalgemology.com/about/how-we-measure/your-own-file)

[All 328 terms](https://digitalgemology.com/learn/glossary)