STL file
A widely used 3D printing format that stores only triangle geometry, without colours, materials or layers.
What STL stores and leaves out
STL stores triangles and their normals. It does not store colours, materials, textures, layer names or units. Most jewelry STL files are in millimetres by convention, but the file itself does not say so. STL can be ASCII text or binary, and binary files are much smaller.
Why jewelers use STL
Casting houses and resin printers expect STL, so almost every jewelry CAD program exports it. It is often the one file a designer already has for every piece.
Rendering from STL
Because STL has no materials and no separate parts, the whole piece arrives as one surface. RenderMyJewels accepts STL uploads and lets you apply a metal material to the model, which works well for plain metal designs such as bands, signets and pendants.
For pieces with stones, an STL cannot separate the stones from the metal, so they share one material. When you need stones to look like stones, export a format that keeps parts separate, such as 3DM, GLB, OBJ or FBX, with the stones on their own layer.
Preparing STL files
- Export binary STL to keep files small.
- Check that the mesh is watertight for printing, which also avoids render gaps.
- Use enough mesh density on curved surfaces, since STL can only describe curves with more triangles.
- Keep uploads within the 100 MB limit for STL files.