Blog · File preparation
Most bad laser cutting jobs start with bad DXF files. This guide shows you how to prepare clean DXFs that cut properly the first time, reduce setup time and avoid the hidden costs caused by messy drawings.
Why DXF quality matters so much for laser cutting
Laser machines do exactly what the file tells them to. If the DXF is full of gaps, overlaps, tiny fragments and scaling issues, the cut will either fail, take longer than it should or require extra time from the programmer to repair the file. All of that shows up somewhere in your quote, your lead time or your quality.
Good DXF files give you
- Faster, more accurate quoting.
- Less back-and-forth and fewer surprises.
- Better edge quality and fit-up in assemblies.
Bad DXF files cause
- Extra programming time to clean and repair geometry.
- Misaligned holes, missing features and scrap parts.
- Delays when issues are found late in the process.
The good news
- Most common DXF problems are easy to avoid once you know them.
- A few simple habits in CAD will save you time and money on every job.
Clean geometry – gaps, overlaps and duplicate lines
The laser controller wants a continuous toolpath. Broken geometry forces the software to guess or fail.
Aim for closed, continuous profiles
- Outer profiles should be closed polylines, not a patchwork of short segments.
- All holes and cut-outs should also be closed loops.
- Use join, weld or polyline tools in your CAD software to tidy outlines.
Remove duplicates and stray geometry
- Delete hidden construction lines, centre lines and dimensions from the export.
- Use tools to detect and delete overlapping or duplicated entities.
- Zoom in on tight corners to confirm you do not have tiny gaps or slivers.
Layers, colours and line types – how to keep it simple
Every shop has its own conventions, but simple DXFs are the easiest to process. You do not need to build a full CAM file – just something clean and unambiguous.
Recommended approach
- Use one main layer for cut lines only.
- Place etch or engraving lines on a clearly named separate layer.
- Freeze or delete any construction, centre or dimension layers before export.
Line types and weights
- Use continuous lines – dashed or dotted lines do not cut differently unless agreed.
- Line weight is usually ignored by the CAM software, but heavy lines can hide detail on screen.
- If you need different processes (cut, etch, fold marks), communicate that clearly in a PDF or note.
Units, scale and origin – avoid tiny or giant parts
One of the fastest ways to derail a job is a DXF exported in the wrong units. What looks right on screen can come in 25.4 times too big or too small if inches and millimetres get mixed up.
Set and confirm units before export
- Work in millimetres for Australian fabrication and signage.
- Check your CAD file's unit settings, not just the dimensions on screen.
- After exporting, reopen the DXF and measure a known feature to confirm.
Use a sensible origin and position
- Keep parts close to the origin (0,0) – not kilometres away in model space.
- Align parts so the longest edge is horizontal where practical.
- For multi-part DXFs, keep a clear gap between parts and avoid overlapping outlines.
Small features, kerf and realistic tolerances
Lasers are accurate, but not magic. Features smaller than the kerf width or material thickness are unreliable, and over-tight tolerances drive up cost without improving function.
Designing small features
- Avoid slots narrower than the material thickness where possible.
- Keep inside corners radiused rather than perfectly sharp.
- Do not rely on ultra-fine tabs or spikes that will burn away or warp.
Tolerances that make sense
- Use realistic general tolerances for laser cut parts – do not specify machining where not needed.
- Call out only truly critical dimensions on drawings or notes.
- Remember that mating parts can share tolerance between them, not carry it all on one component.
Text, engraving and etch lines
Text and logos need different treatment depending on whether you want them cut out, etched on the surface or simply used for internal reference.
If you want text cut out
- Convert text to outlines/curves before export.
- Use stencil-safe fonts or manually add bridges so centres do not fall out.
- Avoid tiny serif fonts that will close up or burn away.
If you want text engraved or etched
- Place etch lines on a clearly named engraving layer.
- Keep line work simple – hatching is usually handled by the CAM software, not your DXF.
- Provide a reference PDF showing what should be cut versus etched.
DXF pre-flight checklist
Before you send files for quoting or cutting, run through this quick checklist. It takes a few minutes in CAD and can save days of back-and-forth later.
- Units: file is in millimetres, and a known dimension measures correctly.
- Geometry: all profiles are closed loops, no stray lines or duplicates remain.
- Layers: one layer for cut, one for etch (if required), everything else frozen or removed.
- Origin and position: parts are near 0,0 with sensible orientation and spacing.
- Features: slot widths, hole sizes and radii are realistic for the material and process.
- Text: converted to outlines or clearly marked as etch, with a PDF reference if complex.
- Notes: material, thickness, quantity and any critical dimensions are specified somewhere clear.
DXF for laser cutting – FAQs
Laser Cutting Experts receives DXF files every day from engineers, architects, industrial designers, signage studios and makers. The difference between a clean, production-ready file and a messy, half-finished export is immediately obvious in how quickly we can price and schedule the job. Clean DXFs move through quoting, nesting and cutting with minimal friction. Untidy files need manual intervention and introduce more opportunities for misinterpretation.
For busy teams, investing a little time in setting up sensible CAD templates – standard layers, default units, export presets and a simple DXF checklist – pays off very quickly. It reduces the number of questions on every order and makes it easier to hand work between team members without losing intent. When you combine well prepared DXFs with a cutting partner that understands both fiber and CO2 laser, CNC routing and digital knife cutting, you unlock much smoother production across metals, plastics, timbers, foams and gasket materials.
Based in Sydney and servicing customers across the East Coast, Laser Cutting Experts is set up to work with professional DXF workflows as well as help newer users get their first files into production. If you are not sure whether your current DXFs are helping or hurting, send a sample set through and we can give you practical, specific feedback rather than generic theory.
