File Formats
Reference guide to file formats supported by CADit for saving, importing, and exporting designs.
File formats
CADit works with several file formats for different purposes: project files for saving your work, 3D printing formats for manufacturing, and image formats for tracing.
Project format
.cadit
The native CADit project format stores your complete design.
Contains:
- All 2D shapes and their properties (color, fill, transform)
- 3D settings (height, sculpt, twist) for each shape
- Space and plane configurations
- Scripts and code objects
- Design metadata and version information
Use for:
- Saving work in progress
- Sharing editable designs with others
- Backing up designs for later editing
- Publishing to the CADit Design Library
File structure: JSON format with embedded binary data for geometry and images. Files can be opened in a text editor for inspection, though editing directly is not recommended.
How to create:
- Menu > Save CADit Project
- Ctrl/Cmd + S
How to open:
- Menu > Open CADit File
- Drag and drop onto the canvas
3D printing formats
.stl
STL (Stereolithography) is the standard format for 3D printing. Supported by virtually all slicers and 3D printers.
Contains:
- Triangle mesh geometry
- No color or material information
Use for:
- Single-color 3D prints
- Maximum compatibility with slicers and printers
- Sharing printable models
Export: Menu > Export STL
Import: Menu > Import STL
When importing an STL file, CADit extracts the 2D outline (silhouette) and creates an editable shape. The original 3D model's height is preserved.
.3mf
3MF (3D Manufacturing Format) is a modern format that preserves color information.
Contains:
- Triangle mesh geometry
- Per-shape color assignments
- Model structure and component hierarchy
- Unit information (millimeters)
Use for:
- Multi-color prints on multi-material printers
- Prints where slicer needs color data to assign filaments
- Designs where color organization matters
Export: Menu > Export 3MF
Not supported for import. CADit can export 3MF but cannot open 3MF files created elsewhere.
Multi-color workflow
When exporting 3MF for multi-material printing:
- Shapes with the same color in CADit are grouped together in the exported file
- Your slicer (PrusaSlicer, Bambu Studio, OrcaSlicer, etc.) detects each color group
- Assign each color group to a filament or extruder in your slicer
The number of distinct colors in your design determines how many material groups appear in the export.
Programmatic export
.obj
OBJ (Wavefront) format is available through Code Mode for programmatic export.
Contains:
- Triangle mesh geometry
- Material references (separate .mtl file)
Use for:
- Integration with other 3D software
- Custom export workflows in scripts
OBJ export is not available through the menu. Use the export API in Code Mode scripts when this format is needed.
Image formats for import
Use the Photo Guide tool to import images for tracing and conversion to 3D shapes.
Supported formats
| Format | Extension | Best for |
|---|---|---|
| PNG | .png | Screenshots, graphics with transparency |
| JPEG | .jpg, .jpeg | Photos, complex images |
| GIF | .gif | Simple graphics |
| BMP | .bmp | Uncompressed images |
| SVG | .svg | Logos, icons, vector graphics |
| WebP | .webp | Modern web images |
Raster vs. vector
Raster images (PNG, JPEG, GIF, BMP, WebP) are traced using edge detection. Results depend on image contrast and clarity. High-contrast images with clear edges work best.
Vector images (SVG) can be traced like raster images, or sampled directly for higher precision. When sampling, CADit extracts the actual vector paths from the SVG file.
How to import images
- Select the Photo Guide tool from the 2D toolbar
- Choose an image file
- Adjust tracing parameters in the parameter panel
- The traced result becomes an editable shape
See Photo Guide for detailed tracing instructions.
Format comparison
| Format | Save | Import | Export | Color | Editable |
|---|---|---|---|---|---|
| .cadit | Yes | Yes | - | Yes | Yes |
| .stl | - | Yes | Yes | No | As 2D outline |
| .3mf | - | No | Yes | Yes | - |
| .obj | - | No | Code only | No | - |
| Images | - | Yes | - | - | As traced shape |
File size considerations
- .cadit files grow with design complexity. Designs with many shapes or imported images may produce larger files.
- .stl files size depends on mesh detail. Complex curved surfaces produce larger files than simple shapes.
- .3mf files are typically similar in size to STL files, compressed in a ZIP container.
Related topics
- Saving designs for cloud, local, and file save options
- Importing files for import workflows
- Exporting for printing for print export details