Bottom surface pattern (bottom_surface_pattern)
Bottom surface pattern is one of a fixed set of names. Cura declares 3 names; PrusaSlicer, Bambu Studio, OrcaSlicer and Creality Print declare none.
What does each slicer call it?
Five slicers, five spellings of one setting. The scope column is which preset the key belongs to, which is what decides whether changing it follows the printer, the filament, or the print profile.
| Slicer | Key | Scope |
|---|---|---|
| PrusaSlicer | bottom_fill_pattern |
process |
| Bambu Studio | bottom_surface_pattern |
process |
| OrcaSlicer | bottom_surface_pattern |
process |
| Cura | top_bottom_pattern |
process |
| Creality Print | bottom_surface_pattern |
process |
What does each slicer say about it?
Each slicer offers its own values, so each gets its own line.
- PrusaSlicer: Pattern for the lowest solid layer facing the bed. Changes how the underside looks.
- Bambu Studio: Line pattern of the bottom surface, such as monotonic line. Bridges over open space are not affected.
- OrcaSlicer: Line pattern for the bottom surface infill, not bridges. Monotonic gives smooth lines; other patterns change the underside texture.
- Cura: Pattern for top and bottom layers, such as lines, concentric or zigzag.
- Creality Print: Line pattern of the bottom surface fill, not bridges. Monotonic gives smooth, even lines.
Where does it live in the file?
All five slicers file this under the process preset, so its value follows the print profile rather than the model. A .3mf is a zip, so unzip it and search for bottom_fill_pattern, bottom_surface_pattern and top_bottom_pattern, or open the file in preslice and read the Raw tab, which searches every member at once.
Four of the five slicers write their settings into a sidecar part beside the geometry. Cura writes them into the model XML itself, so there is no config part to open.
| Slicer | Part | Format |
|---|---|---|
| PrusaSlicer | Metadata/Slic3r_PE.config |
INI, one key = value per line |
| Bambu Studio | Metadata/project_settings.config |
JSON, one flat object |
| OrcaSlicer | Metadata/project_settings.config |
JSON, one flat object |
| Cura | 3D/3dmodel.model |
XML metadata inside the model part, under a cura namespace |
| Creality Print | Metadata/project_settings.config |
JSON, one flat object |
What values are valid?
Each slicer declares its own type, default, and bounds for its key. They do not always agree, and where they disagree the file is still valid in both: the slicer that wrote it is the one that enforced its own rule.
| Slicer | Type | Unit | Default | Range |
|---|---|---|---|---|
| PrusaSlicer | enum | not declared | not declared | not declared |
| Bambu Studio | enum | not declared | monotonicline |
not declared |
| OrcaSlicer | enum | not declared | monotonic |
not declared |
| Cura | enum | not declared | lines |
3 named values |
| Creality Print | enum | not declared | monotonic |
not declared |
PrusaSlicer, Bambu Studio, OrcaSlicer and Creality Print declare no range for this key, so nothing in the file bounds it.
This value is not a number, so PrusaSlicer, Bambu Studio, OrcaSlicer, Cura and Creality Print declare no unit for it.
Cura accepts the same names: concentric, lines, zigzag.
Every type, default, and bound above is read from the slicer's own field definitions rather than from measurement: PrusaSlicer's PrintConfig.cpp, Bambu Studio's PrintConfig.cpp, OrcaSlicer's PrintConfig.cpp, Cura's fdmprinter.def.json and Creality Print's PrintConfig.cpp.
Can I read it from my own file?
Yes, without installing a slicer. Open preslice and drop a .3mf on the page. It unzips and parses the file in your browser, and shows bottom surface pattern under its own name alongside the rest of the print settings. The file stays in your browser; see what leaves it.