Laser Cutting and CNC¶

A laser cutter doesn't admire your artwork. It follows paths. Every vector stroke in your Vexy Lines export becomes a command: move here, fire the laser, cut or engrave. The difference between a successful cut and a charred mess is whether those paths were designed for a machine rather than a screen.

This article covers the translation from Vexy Lines vector output to machine-ready files for laser cutters, CNC routers, and vinyl cutters.

Two Operations: Cut and Engrave¶

Laser cutters perform two fundamentally different operations, and Vexy Lines handles both:

Operation	What the Laser Does	Vexy Lines Fill	SVG Element
Cut	Burns through the material along a path	Trace (outlines)	Stroke (no fill)
Engrave	Rasters or scores the surface following a path	Linear, Halftone, Wave, etc.	Stroke (no fill)

Cutting follows the path once and severs the material. You want clean closed paths: the outlines of the shapes you're cutting out.

Engraving follows the path to mark the surface without cutting through. You want fill patterns: the decorative strokes that texture the surface.

Most laser projects use both: Trace fills for the cut paths, Linear/Halftone/Wave fills for the engraved decoration.

Layer Colour Coding¶

Most laser software (LightBurn, LaserGRBL, Glowforge, RDWorks) uses path colour to determine operation type and settings. The convention:

Colour	Operation	Typical Settings
Red	Cut (through)	High power, low speed, single pass
Black	Engrave (mark surface)	Lower power, higher speed, single or multiple passes
Blue	Score (light surface mark)	Low power, high speed

In Vexy Lines:

Set your Trace fill (cut paths) colour to red.
Set your shading fills (engrave patterns) colour to black.
Set any light score marks colour to blue.

When the laser software imports the SVG, it automatically groups paths by colour and applies the corresponding power/speed settings.

Trace for Cutting¶

The Trace fill generates the contour paths that become your cut lines. For laser cutting, set it up carefully:

Parameter	Value	Why
Smoothing	40–60	Enough to avoid jagged corners but not so much that sharp features round off
Min Spot Size	8–15 px	Eliminates tiny contour fragments that the laser would try to cut, wasting time and potentially damaging the material
Threshold	Adjusted to capture only the edges you want to cut	Too sensitive = too many contours = confusing cut paths
Colour	Red (or your laser software's cut colour)	Identifies these paths as cut operations

Closed Paths¶

Laser cutting requires closed paths: the path must start and end at the same point to cut out a complete shape. Trace fills in Vexy Lines typically produce closed contours, but complex images can generate open paths (contours that run off the canvas edge).

After export, open the SVG in a vector editor and verify that cut paths are closed. Most laser software will also warn about open paths.

Linear and Halftone for Engraving¶

Fill patterns become the engraved decoration on the material surface. The laser follows each stroke path, scoring the surface.

Linear Engraving¶

Parameter	Value	Why
Interval	0.5–1.5 mm (depends on material and laser)	Must be wider than the laser beam width (typically 0.1–0.3 mm)
Angle	Your choice: 0°, 45°, or matching the design	Affects visual texture of the engraved surface
Smoothing	50–70	Smooth paths mean fewer direction changes, which means cleaner engraving
Stroke Thickness	Set to a single weight (0.2–0.5 mm) or use brightness mapping	Single weight for consistent engraving depth; mapped weight for variable depth
Randomization	0–5%	Machines don't benefit from randomization; keep paths predictable
Colour	Black	Identifies as engrave operation

Halftone Engraving¶

Halftone fills produce dot patterns where the laser engraves individual dots of varying sizes. The effect on wood or acrylic is striking: a photographic image rendered as burned dots.

Parameter	Value	Why
Shape	Circle	Circles engrave most cleanly (no sharp corners for the laser to navigate)
Mode	Grid	Predictable spacing prevents overlapping burns
Interval	1.0–2.0 mm	Spacing between dot centres; must accommodate the largest dot
Colour	Black	Engrave operation

Critical: Minimum Detail Size¶

Every laser has a beam width: the diameter of the focused laser spot. This is typically:

CO2 lasers: 0.1–0.3 mm
Diode lasers: 0.08–0.15 mm
Fibre lasers: 0.02–0.05 mm

No stroke or gap in your design should be smaller than the beam width. If the laser beam is 0.2 mm wide and your fill produces strokes with 0.15 mm gaps between them, the laser will burn through the gaps, turning your engraving into a cut.

Safe minimums:

Detail	Minimum Size
Stroke thickness	Beam width × 1.5 (e.g., 0.3 mm for a 0.2 mm beam)
Gap between strokes	Beam width × 2 (e.g., 0.4 mm for a 0.2 mm beam)
Smallest Halftone dot	Beam width × 3 (e.g., 0.6 mm for a 0.2 mm beam)
Interval	Stroke thickness + gap (e.g., 0.7 mm minimum)

Stroke vs. Fill in SVG¶

This is a critical technical distinction for laser work:

Stroke (vector path with a line width) = the laser follows the path. This is what you want.
Fill (enclosed shape filled with solid colour) = the laser rasters the enclosed area back and forth. This is slower and sometimes undesirable.

Vexy Lines exports strokes as vector paths, which is correct for laser work. But be aware:

Some vector editors convert strokes to filled outlines during editing. If you edit the SVG in Illustrator, verify that paths remain as strokes, not filled shapes.
Some laser software interprets thick strokes differently than thin ones. Test with your specific software.

Materials¶

Different materials respond differently to laser engraving and cutting. Here's how Vexy Lines parameters should adjust:

Wood (Plywood, MDF, Hardwood)¶

Engraving: Linear or Halftone at 1.0–1.5 mm interval. Wood engraves beautifully with visible burn contrast.
Cutting: Trace outlines. Multiple passes may be needed for thick stock.
Tip: Wider intervals (2.0+ mm) on softwoods like pine, which burn more aggressively. Tighter intervals (1.0 mm) on hardwoods like maple, which handle detail well.

Acrylic¶

Engraving: Produces a frosted white mark on clear acrylic. Halftone fills look especially good: the frosted dots catch light.
Cutting: Clean edges when well-calibrated. Trace outlines work perfectly.
Tip: Acrylic melts rather than burns. Tight intervals (< 0.8 mm) can cause melting between strokes. Keep intervals at 1.0 mm+.

Paper and Cardboard¶

Engraving: Light scoring. Reduce laser power significantly. Linear fills at 1.5–2.0 mm interval.
Cutting: Easy to cut. Trace outlines with single pass.
Tip: Paper is the ideal test material. Run every design on cardboard first before committing to expensive stock.

Leather¶

Engraving: Beautiful results. The burn darkens the leather surface. Linear and Wave fills produce an embossed-leather effect.
Cutting: Works well for thin leather (< 3 mm).
Tip: Leather warps when heated. Use wider intervals (2.0+ mm) and multiple light passes instead of one heavy pass.

Metal¶

Engraving only (most hobby lasers can't cut metal). Fibre lasers engrave metal directly; CO2 lasers need marking spray.
Tip: Keep intervals tight (0.5–0.8 mm) on metal: the marks are subtle and benefit from density.

The Test-on-Cardboard Rule¶

Never run a design on your final material without testing on cardboard first. Cardboard is cheap, cuts easily, and reveals problems:

Are the cut paths closed? (If not, the piece won't separate.)
Are the engrave intervals wide enough? (If strokes merge into solid burns, widen the interval.)
Are there tiny fragments? (If the laser spends time on microscopic contours, increase Min Spot Size in the Trace fill.)
Does the design fit? (Print at 1:1 or cut on cardboard at 1:1 to check physical dimensions.)

Export Settings¶

Setting	Value
Format	SVG
Colour coding	Red = cut, Black = engrave, Blue = score
Canvas size	Match material dimensions
Smoothing	40–60 on all fills
Stroke output	Paths (not filled outlines)

After exporting, open the SVG in your laser software and verify:

Cut paths (red) are closed and form complete shapes.
Engrave paths (black) are within the material boundary.
No paths extend beyond the material dimensions.
Path count is reasonable (thousands, not millions; a million paths will take hours to process).

Summary¶

Vexy Lines Fill	Laser Operation	Colour	Key Parameters
Trace	Cut	Red	Smoothing 40–60, Spot Size 8–15 px
Linear	Engrave	Black	Interval ≥ beam width × 3, Randomization 0–5%
Halftone	Engrave	Black	Circle shape, Grid mode, Interval ≥ 1.0 mm
Wave	Engrave	Black	Smoothing 50+, moderate amplitude

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