How to design parts for laser cutting
Files that follow these rules quote cleanly in our pricing engine, nest tightly on the sheet, and cut right the first time — no back-and-forth with your operator.
Best file formats for online laser cutting
KERF accepts 2D vector files (your part outlines) and 3D STEP files (we extract the flat pattern automatically). Send us what your CAD or design tool exports natively — we'll handle the conversion.
| Software | Accepted extensions |
|---|---|
| Fusion 360 | .dxf, .step, .stp |
| SolidWorks | .dxf, .step, .stp |
| AutoCAD | .dxf, .dwg |
| Inkscape | .svg, .dxf, .eps |
| Adobe Illustrator | .ai, .svg, .dxf, .eps |
| Vectornator / Affinity | .svg |
| CorelDraw | .eps, .dxf, .svg |
| Onshape | .dxf, .step |
File requirements — the short version
Most uploads that fail our auto-quote miss one of these. If you've got two minutes before sending us a file, walk this list:
- Artwork is correctly scaled — 1:1, in millimetres.
- File contains only your parts and cut paths — nothing else.
- All text has been converted to shapes / outlines.
- Letters with closed loops (a, e, o, d) are stencilised or bridged.
- Every hole and interior cutout is at least 50% of the material thickness.
- No two cut lines overlap, intersect or share a path.
- No open contours — every shape closes back on itself.
- No stray points, duplicate lines or empty objects.
Send artwork at 1:1, in millimetres
KERF cuts whatever size your file says. We don't scale your art up or down to fit a sheet — we trust the dimensions you sent. A 1:1 file means a 100 mm line in your CAD is a 100 mm line on steel.
South African convention: we accept millimetres only. No centimetres, no metres, no inches. If your CAD defaults to inches (most US-origin tools do), switch before you export, or scale by 25.4 in Inkscape after export.
- · Set your CAD doc units to mm before drawing.
- · Export DXF with units = mm. Re-import to double-check.
- · If you traced a raster, print the result and measure it.
- · Don't send 'pixel'-unit SVGs from Photoshop or Figma.
- · Don't rely on % widths in your SVG header — we treat those as unknown.
- · Don't assume we'll size to your photo of the part. We won't.
Files should only contain your parts
Anything that isn't a cut path is noise that has to be cleaned up before the file can be programmed. Drawing borders, title blocks, dimension lines, construction circles, hidden layers, hatched section views, leader arrows — strip all of it.
DXF for Laser from the sketch context menu — it strips construction geometry automatically. In SolidWorks, use Save As → DXF/DWG → Export options: geometry only.Convert all text to shapes / outlines
A laser cuts along vector paths. Live text isn't a vector path until it's "outlined" — the font has to be present on the programming computer or your letters render as Arial. Don't risk it.
- · Illustrator: select text → Type → Create Outlines (⇧⌘O).
- · Inkscape: select text → Path → Object to Path (⇧⌘C).
- · Fusion 360: in sketch, right-click text → Explode Text.
- · SolidWorks: dissolve sketch text into entities before saving DXF.
- · Don't leave live, editable text in the file.
- · Don't assume the font will travel with the file. Often it doesn't.
- · Don't use bitmap text (e.g. typed into Photoshop) — that's a raster.
Stencilise or bridge any letter with a closed loop
Cut the letter "O" out of a sign and the middle disc falls to the floor. Same with A, B, D, P, Q, R, a, b, d, e, g, o, p, q, 0, 4, 6, 8, 9. Two options: switch to a stencil font (Allerta Stencil, Stencil Std, Glaser Stencil) or add a tiny "bridge" — a 1–2 mm wide segment that holds the inner shape to the outer.
Holes and cutouts: at least 50% of material thickness
Lasers cut a small slot (the "kerf") rather than punch a hole. Below 50% of material thickness, the kerf width starts eating most of the hole and you end up with a melted slag-filled dimple instead of a clean circle.
| Material thickness | Minimum hole / cutout |
|---|---|
| 1 mm | 0.5 mm |
| 2 mm | 1 mm |
| 3 mm | 1.5 mm |
| 5 mm | 2.5 mm |
| 8 mm | 4 mm |
| 10 mm | 5 mm |
| 12 mm | 6 mm |
Need holes smaller than this? Switch to drilling — KERF can quote it as a secondary op.
No overlapping or intersecting cut lines
When two parts share an edge in your file ("common-line cutting"), our nester can't tell which side to keep. Worse, two stacked lines cause the laser to cut the same path twice — wasting time and burning the edge. Even within a single part, double-clicked duplicate lines confuse the postprocessor.
- · Run Inkscape's Path → Simplify, then visually check for overlaps.
- · In Illustrator: Object → Path → Clean Up → remove stray points.
- · Use the 'Find Identical' tool in your CAD to surface duplicates.
- · Don't manually butt two parts together to save material — let our nester do it.
- · Don't double-trace a path 'to make it bolder' — it doesn't, it just breaks.
Close every contour — no gaps
An "open contour" is a shape that doesn't loop back to its start point. Our auto-nester treats them as cut lines rather than closed shapes, which means the laser will run along the line and stop, but you'll have a slot in your sheet rather than a removable part.
Edit → Find/Replace → Properties → Open paths. In Illustrator, the Object → Path → Join command (⌘J) closes any selected open shape. In CAD, run a "close open polylines" macro before exporting your DXF.Tutorials for the tools you probably use
We'll keep adding to this as we see more partner-shop files. If your tool isn't here and you're stuck, email vernon and we'll walk you through it.
Export a flat pattern as DXF for laser. Includes joints and bend lines.
Save flat sheet-metal parts to DXF without construction geometry.
Set up artboards in mm, convert text to outlines, export as DXF.
Free + powerful. Trace bitmap, set scale, export DXF for the laser.
Preflight checklist
Run this once before you upload. Catches roughly 95% of the "your file failed auto-quote" reasons. Print it, pin it next to your machine, whatever helps.
- File is one of: DXF, DWG, SVG, AI, EPS, STEP, STP
- Units are mm
- Drawing is 1:1 scale
- All cut paths are on a single layer
- All text converted to outlines / paths
- Letters with closed loops are stencilised or bridged
- All holes and cutouts ≥ 50% of material thickness
- All shapes are closed (no open contours)
- No overlapping, duplicate or intersecting lines
- No stray points, hatch fills or dimension lines
- No title block, border or notes — only the parts
- Material and quantity decided before uploading
Materials we cut on the laser
Live from our partner network. Click any material to start a quote with it preselected. Don't see what you want? Ask — most things are sourceable, we just don't carry them as standard.
All thicknesses in mm. KERF cuts to whichever sheets your chosen partner stocks — if the thickness you want isn't shown, it's likely possible on a per-job basis.
Frequently asked
Can I send a sketch on the back of a serviette?+
What's the tightest tolerance I can expect?+
Do you charge extra for tiny holes?+
Can you engrave (not cut) text on the part?+
ENGRAVE and we'll set the laser to low-power outline mode for that geometry. Adds a small per-mm fee on top of the cut rate.What if my file fails the auto-quote?+
Upload your design. Get a real price in under a minute.
Drop your DXF, SVG or STEP file — we'll size, nest and quote it on the spot. No login. No phone calls. Pay when you're ready.
More guidelines
Every cutting and secondary-ops service we offer, with the design rules that matter.