When you're ready to send your model to the slicer (like Cura, PrusaSlicer, or Bambu Studio), you have a choice to make. Do you stick with the trusty STL, or upgrade to a modern format?
STL: The Old Reliable
STL (Stereolithography) has been the standard since the 80s. It describes the surface geometry of a 3D object without any representation of color, texture, or other common CAD model attributes.
- Pros: Every slicer opens it. It's simple.
- Cons: High file sizes for detailed curves. No color. No units (millimeter vs inch confusion).
OBJ: When You Need Color
OBJ files are commonly used when color information is important. If you are doing multi-color printing (like with an AMS or MMU system), OBJ files can sometimes carry the necessary split-part information better than a single STL.
However, OBJ files are text-based, making them slower to read and larger on disk than binary formats.
3MF: The Modern Standard
3MF (3D Manufacturing Format) is designed specifically for additive manufacturing. It solves almost every problem with STL.
Why 3MF Wins:
- Small Size: It uses ZIP compression (like .docx).
- Rich Data: Contains units, color, textures, and even printer settings.
- No Errors: Designed to prevent "non-manifold" geometry errors.
If your slicer supports it (and most modern ones do), use 3MF. It's smaller, safer, and smarter.