Exporting DXF for CNC and Laser Cutting

DXF (Drawing Exchange Format) is how you get a design from a computer into a fabrication machine — laser cutters, CNC routers, vinyl plotters, and waterjet machines all speak DXF. Here's how to produce a clean one from a raster image.

The unique challenge of cut paths

Unlike print output, DXF files for CNC/laser need to be closed paths — every shape needs a defined interior. An open path confuses most CAM software and can result in incomplete cuts or the machine not knowing where to start.

Vectalyze outputs closed paths wherever possible. But the quality of your input image heavily affects the result.

Best source images for DXF

• High contrast: Pure black on white, or black on transparent. Avoid gradients.
• Clean edges: Blurry or anti-aliased edges produce wobbly paths that need manual cleanup.
• Simple geometry: The fewer distinct regions, the cleaner the DXF. Complex illustrations produce complex paths.

Recommended trace settings

For DXF output, use these as a starting point:

• Threshold: 150–200 (lean white to ensure solid fills)
• Turd size: 10–20 (discard small noise regions that would produce micro-cuts)
• Smooth: 0.5–1.0 (preserve corner sharpness that fabrication machines expect)
• Optimise: On (reduces node count without affecting shape)

Kerf compensation

Vectalyze doesn't apply kerf compensation — that's the responsibility of your CAM software. If you're laser cutting 3mm acrylic with a 0.2mm kerf, adjust paths inward by 0.1mm in your CAM tool (Lightburn, Fusion 360, RDWorks, etc.).

Checking the DXF before cutting

Open the DXF in your CAM software and verify:

• All paths are closed (look for open endpoints shown in red or orange)
• Node count is reasonable — fewer nodes = smoother cuts
• Scale is correct (DXF is unitless; confirm your CAM tool is interpreting it at the right size)
• No overlapping paths that would cause double-cutting

Nested parts

If you're nesting multiple parts for sheet efficiency, do the nesting in your CAM software after importing the DXF — not before generating it. Nesting in the source image makes it impossible for the tracer to separate individual shapes.