Published 2026-09-01 · 2 min read
STL, OBJ or GLB: which format to export
3D formats are not interchangeable. Each was invented for a different job and throws away what it does not care about. The wrong choice means a model that arrives grey, inside out, or ten times too small.
STL — for printing
The simplest format possible: a list of triangles, and nothing else. No colours, no materials, no units, no object names. That is exactly why it is universal — every slicer and every 3D program opens it.
Use it when the destination is a 3D printer. Pick binary, not ASCII: the same model takes about five times less space.
OBJ — for moving between programs
Plain text with geometry, texture coordinates and group names. Materials live separately in an .mtl file that is easily lost along the way.
It is the safest choice when you send geometry to someone working in another program and want to keep objects separated.
GLB — for showing
A single file holding geometry, materials, textures and hierarchy. It opens directly in web viewers, on phones, in Windows, in presentations.
This is what you send a client who just wants to look: they open it on a phone with nothing installed and spin it with a finger.
SVG — for plans and print
Not a 3D format at all, but the vector drawing that results from cutting the model at a given height. It opens in any drawing program, scales without pixelation and prints to exact scale.
In GrafitGo you cut the building at whatever level you want and export the plan as SVG, with walls, openings and dimensions. That is the file you hand to a builder or take to a print shop.
The short rule
- Going to a printer → binary STL.
- Going to a colleague in another program → OBJ.
- Going to a client who only looks → GLB.
- Going on paper or to a builder → SVG.
- Staying with you for more work → your own project file with its parameters; every other format loses them.
Why did my export lose its colours?
Because STL has nowhere to keep them. If you want colours and materials, export GLB.
Can I reimport an STL and edit it parametrically?
No. An STL is a triangle mesh: you can cut it, join it and scale it, but the original parameters cannot be recovered from triangles.
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