Clipping & cropping
Clipping and cropping both restrict a job to a region — they're how you fit production to the material you actually have on the bed. The difference is shape: crop is a rectangle, clip is any SVG path.
Both are configured through the same node in the workflow editor (Clip / Crop) or as part of a job preset. The toggleCropClip parameter switches between the two modes.
When to use which
| If you have… | Use… |
|---|---|
| A new rectangular sheet of stock. | Crop. |
| An irregular offcut from a previous job. | Clip with an SVG path traced around the offcut. |
| A jig with bolted-down fixtures you can't burn over. | Clip with a path that excludes the fixtures. |
| A rotary attachment with a curved usable surface. | Clip with the curved bounds. |
Cropping (rectangular)
Cropping limits a job to a rectangle in machine coordinates. The G-code is trimmed to the bounding box at compile time using a Cohen-Sutherland line clipper — output stays valid G-code, just shorter.
Crop parameters
| Parameter | Type | Default | What it does |
|---|---|---|---|
toggleCropClip | checkbox | off | Off = rectangular crop mode. On = SVG-path clip mode. |
cropMinX | number (mm) | 0 | Left edge of the crop rectangle. |
cropMaxX | number (mm) | 100 | Right edge. |
cropMinY | number (mm) | 0 | Bottom edge. |
cropMaxY | number (mm) | 100 | Top edge. |
Clipping (SVG path)
Clipping limits a job to an arbitrary SVG d path. Anything outside the path is removed at the G-code level, using the Cython path-clipper that ships with GRBL Server (it's fast — clipping a 200-piece grid against a curved path takes milliseconds).
Clip parameters
| Parameter | Type | Default | What it does |
|---|---|---|---|
toggleCropClip | checkbox | off | Turn this on to use clip mode. |
clipApproximation | number | 0.01 | Curve flattening tolerance, in mm. Smaller = more accurate, slower. 0.01 is good for visible cuts; 0.1 is fine for engraving. |
clipTextarea | textarea | (empty) | The SVG path's d attribute — the same string you'd put in <path d="..."/>. |
Getting the SVG path
You need an SVG d string. A few ways:
- Trace it in Inkscape / Illustrator, then copy the
dattribute out of the saved SVG. - Hand-write it for simple shapes — circles, rounded rectangles, polygons.
M 30 30 Q 80 10 130 30 T 230 30 L 250 100 Q 240 160 180 170 L 80 170 Q 30 160 30 100 Zis a soft pebble shape. - Photograph the offcut on a phone, drop it into Inkscape, run Path → Trace Bitmap, copy the result.
Example: a hexagonal offcut
M 50 0
L 150 0
L 200 86.6
L 150 173.2
L 50 173.2
L 0 86.6
ZDrop that string into clipTextarea, turn on toggleCropClip, and the job is restricted to the hexagon.
The pre-visualizer
Before any job runs, the pre-visualizer canvas shows you the working area with the clip / crop region overlaid and the actual G-code paths drawn inside. Use it. A 5-second look at the pre-visualizer prevents about 80% of wasted-material situations.
The pre-visualizer is opened from:
- The Pre-visualizer data button on any preset (Configuration → Presets).
- The Job station view of a connected machine.
- The Set up job page when configuring a one-off job.
Combining with grids and presets
Clipping composes well with grids — tile across the bed, then clip to the offcut. Cells fully outside the clip are skipped entirely (no wasted moves); cells partially inside are clipped at the G-code level (you get the part of the design that fits).
For repeat use of the same clip path (e.g. you keep cutting from the same jig), save it as part of a preset so you don't paste the SVG path every time.