Guides

Short answers to the file problems that come up most when you 3D print.

• What is an STL file?An STL file is a 3D shape made of triangles. It's the file most 3D printers and slicers expect, because it holds the shape and nothing else.
• 3MF vs STL: which one should you use?Use 3MF when you can, and STL when something only takes STL. 3MF holds the shape plus the unit, colours, parts and settings. STL holds the shape only.
• From Blender to a 3D printSet Blender to millimetres, make the mesh solid, check that walls are thick enough, then export an STL. Here's each step and the menu it lives in.
• Non-manifold edges, explainedA non-manifold edge is a spot where the mesh couldn't exist as a real, solid object. Slicers need a solid to work out what's inside, so they warn you or print it wrong.