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How to Prepare a File for Laser Cutting: The Complete 2026 Guide

Getting your file right before you send it to a laser cutter saves time, money and frustration. A poorly prepared file means delays, re-quotes or cuts that don’t look how you expected. This guide walks you through exactly how to prepare a DXF, SVG or AI file for laser cutting — so your job runs smoothly the first time.

The Golden Rules: Colour Coding

Laser cutting software reads your file using line colour to determine what to do with each path:

• Red (RGB 255, 0, 0) — Cut through. The laser cuts completely through the material along this line.
• Black (RGB 0, 0, 0) — Engrave/etch. The laser rasters or vectors along this line, marking the surface without cutting through.
• Blue (RGB 0, 0, 255) — Also engrave, typically used for a second engrave pass or lighter etch.

Any other colours in your file will either be ignored or cause errors. Do a final colour check before exporting.

Set Your Document Units to Millimetres

This is the most common mistake. If your document is set to inches or points and the file doesn’t include unit metadata, your job will be cut at the wrong scale. Always work in millimetres and confirm your document settings before exporting.

In Adobe Illustrator: File → Document Setup → Units → Millimeters
In Inkscape: File → Document Properties → Display Units → mm
In AutoCAD / DXF: Set $INSUNITS to 4 (millimetres) in your DXF header.

Convert Text to Outlines

If your file contains text, convert all type to outlines/paths before saving. If you don’t, the laser cutter won’t have the fonts installed and your text will either be missing or substituted with a default font.

In Illustrator: Select all text → Type → Create Outlines (Shift+Ctrl+O)
In Inkscape: Select all text → Path → Object to Path

Use Hairline Stroke Weights for Cut Lines

Cut lines should be set to the thinnest possible stroke — 0.001pt or “hairline” in CorelDRAW. A thick stroke is decorative and represents a visual width, but the laser always cuts on the centre of the path regardless. Thick strokes just make it harder to see your design clearly.

Close All Paths

Open paths — lines that don’t connect back to their start point — cause unpredictable results. The laser may skip, stutter or not register the cut cleanly. In Illustrator, use Object → Path → Join to close open anchors. In Inkscape, check Extensions → Generate from Path → Interpolate.

Our prepress process checks for open paths before we cut, but closed paths mean fewer back-and-forth emails.

Remove Duplicate Lines

Overlapping or duplicate lines cause double-cutting — the laser passes over the same path twice, scorching the material or leaving a wider kerf than intended. Select all and use your software’s “Remove Duplicate Objects” or “Delete Duplicate Paths” tool before exporting.

Check Minimum Feature Size

Very small features — thin bridges, small holes, fine text — can be tricky to cut cleanly depending on the material and thickness:

• 3mm acrylic: minimum bridge/feature width 2mm
• 5–10mm acrylic: minimum bridge 3–4mm
• MDF/timber: similar to acrylic at the same thickness

Anything finer than 2mm will likely either fall out, burn, or not hold structural integrity. If you have intricate detail, send us the file first and we’ll advise.

Best File Formats to Send

Quick Checklist Before You Send

1. ☑ Cut lines are RED (255,0,0) — engrave lines are BLACK or BLUE
2. ☑ Document units set to millimetres
3. ☑ All text converted to outlines/paths
4. ☑ Stroke weight on cut lines is hairline / 0.001pt
5. ☑ All paths are closed
6. ☑ No duplicate or overlapping lines
7. ☑ Minimum feature width ≥ 2mm for 3mm material
8. ☑ File saved as DXF, SVG, AI or vector PDF

Still not sure? Upload your file to our Cut File Quote tool — it parses DXF and SVG files instantly, calculates your cut path length, and gives you a live price. Or email us at design@lasercutpacksend.com.au and we’ll check it for free.