Image to DXF for laser cutting
Updated October 25, 2026 · Rasterklar
Short answer
Trace the image into closed outlines, one layer per colour, in millimetres, and save them as DXF Release 12 (AC1009), the version laser and CNC programs read (Autodesk DXF reference). Rasterklar writes exactly that from a PNG or JPG and parses the file back to check it before you download; DXF needs a pass, $5 for 20 images.
Laser and CNC software wants geometry, not pixels: closed outlines it can cut, on layers it can assign to cut, score or engrave settings, at the right size. The DXF the tracer writes is built for that, and it is checked before you get it.
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What is in the DXF
A HEADER section declaring AutoCAD Release 12 and millimetre units with the drawing extents; a TABLES section with one layer per colour, named after the colour (COLOR_1_000000, COLOR_2_C0267A…) and given the nearest AutoCAD colour index so the layers look different on screen; an ENTITIES section of closed POLYLINE entities, one per outline or hole, each on its colour’s layer.
Bézier curves from the trace are flattened into short straight segments so that no point strays more than 0.02 mm from the curve, well under a laser’s kerf. Y is flipped (images grow downwards, DXF grows upwards), so the design is not mirrored.
HEADER $ACADVER AC1009 (Release 12) · $INSUNITS 4 (millimetres) · $EXTMIN / $EXTMAX
TABLES LAYER COLOR_1_1A1A1A (colour 7) · LAYER COLOR_2_C0267A (colour 6) · …
ENTITIES POLYLINE closed (70 = 1) on COLOR_1_1A1A1A → VERTEX × n → SEQEND
POLYLINE closed on COLOR_1_1A1A1A (a hole) → …
POLYLINE closed on COLOR_2_C0267A → …
EOFGetting the size right
A pixel has no size until you say how many fit in an inch. The tracer converts with your DPI: millimetres = pixels × 25.4 ÷ DPI. The preview shows the result before you download.
| Longest side | 96 DPI | 150 DPI | 300 DPI | 600 DPI |
|---|---|---|---|---|
| 480 px | 127.0 mm | 81.3 mm | 40.6 mm | 20.3 mm |
| 1,200 px | 317.5 mm | 203.2 mm | 101.6 mm | 50.8 mm |
| 3,000 px | 793.8 mm | 508.0 mm | 254.0 mm | 127.0 mm |
In LightBurn and other laser software
- Import the DXF: each colour layer arrives as its own set of shapes; assign cut, score or fill per layer.
- Holes are separate closed polylines inside the outer ones; a fill engraving treats them as holes, a cut cuts them out.
- For an outline-only cut of a filled design, black and white mode gives one layer; for a two-pass job (engrave one colour, cut another), colour mode gives one layer per pass.
- If your software reads SVG better than DXF, the SVG has the same shapes in millimetres too.
From image to laser job
- Trace. Drop the image on the tracer and pick the “Laser engrave or cut (DXF)” preset.
- Size. Set the DPI so the millimetre size in the preview matches the job.
- Check the layers. In colour mode, check that each colour you want as a separate pass is its own layer in the preview list.
- Download the DXF. Enter your pass and download the DXF (full resolution, validated).
- Import. Import into LightBurn (or your CAM software) and assign a cut or engrave setting per layer.
Questions
Why R12 and not a newer DXF?
R12 needs no handles, objects section or splines, and every program that reads DXF reads it. Newer versions add nothing a cut outline needs.
Are the curves splines or arcs?
Neither: closed polylines of short straight segments within 0.02 mm of the traced curve. Splines and arcs are read inconsistently across laser software; polylines are not.
Is DXF in the free tier?
No. The free tier gives the reduced-size SVG; full resolution and DXF need a pass. Both formats of the same image count as one image.
Read next
Sources
- Autodesk — DXF Reference, AutoCAD Release 12 (AC1009) group codes (dated February 1, 2011)
- LightBurn documentation — importing SVG and DXF files (dated October 24, 2026)
- Potrace — Peter Selinger, "Potrace: a polygon-based tracing algorithm" (the algorithm; GPL-2.0) (dated September 20, 2003)