STL File
Also called stereolithography file, .stl, stl
An STL file is a 3D file format that stores a design as a mesh of triangles. It records shape only, with no colour, metal, stone, or material data, which is why a renderer has to be told separately what the piece is made of.
In other words, think of it as the outline of the object with everything else stripped out. The form survives the export, the material information does not.
How an STL file works
STL describes a surface as thousands of flat triangles stitched edge to edge. A curved shank is not really curved in an STL, it is a run of very small triangles that read as curved once there are enough of them.
That triangle count is set when you export, and it decides how smooth the piece looks. Export coarse and a polished band will show faint flat facets under a bright light, which is the one STL problem that shows up in renders more than anywhere else.
The format was built for 3D printing, and it stays the standard for sending a model to a printer. It carries no layers, no names, no units in some cases, and no materials.
Why it matters for rendering
STL renders perfectly well, but it arrives silent about everything except shape. We cannot read from the file whether the shank is yellow gold, whether the centre is a diamond or a moissanite, or whether the halo stones are set in white metal against a rose band.
So the more you tell us alongside an STL, the closer the first draft lands. Metal colour, stone types, stone sizes, and finish. Two revision rounds are included, but a good brief means you probably only need one.
Fine detail is the other thing to watch. Milgrain beading, engraving, and pave seats are exactly the areas where a low triangle count turns crisp geometry into mush at high resolution.
- Export at a fine or high mesh setting, not the default draft setting
- Check the model is watertight, with no gaps between surfaces
- Keep stones in the file if you want them rendered, do not delete them
- Confirm the units, so a 17mm ring does not arrive as a 17cm one
STL against the other formats we take
We accept 3DM, STL, OBJ, and STEP. STL is the most common thing people send and the least informative. 3DM keeps your original Rhino surfaces and layer names, which usually gives us the cleanest starting point. OBJ can carry basic colour and texture. STEP keeps exact solid geometry rather than triangles.
If you have a choice, send 3DM. If STL is what you have, send it and tell us the materials.
Questions about STL File
Can you render from an STL file?
Yes. STL is one of the four formats we accept, alongside 3DM, OBJ, and STEP. Just send the material details with it, because an STL carries no metal or stone information.
Why does my STL render look faceted?
The file was exported with too few triangles. Re-export from your CAD program at a fine or high mesh setting and the curves will read as smooth.
Does an STL file contain the gemstones?
Only if the stones were modelled and left in before export. STL saves whatever geometry is there, so if the stones were hidden or deleted, the render will show empty settings.