SVG for Laser Cutting
Laser cutters use SVG paths to define cut, score, and engrave operations. This guide covers how to create and structure SVG files correctly for laser cutting software including LightBurn and LaserGRBL.
About SVG for laser cutting
Laser cutters follow vector paths mathematically. An SVG file defines the exact path the laser head will follow. Cut paths, score paths, and engrave fills are all defined by different SVG elements and colours. Structuring the SVG correctly ensures the laser cutter interprets each operation as intended.
SVG colour coding for laser cutting: most laser software uses stroke colour to distinguish between operations. Common conventions: • Red stroke (#FF0000): cut path (laser cuts through the material) • Blue stroke (#0000FF): score/fold line (laser cuts partway through) • Black fill or hatched fill: engrave area (laser removes surface material) Verify your software's colour conventions in its documentation — LightBurn, for example, uses a priority-based layer system where each layer colour corresponds to a power and speed setting.
Correct SVG structure for cutting: • Use stroke for cut paths, not fill. Cut paths should have a stroke but no fill. • Set stroke width to 0.001 in (or equivalent in your unit system) to indicate a hairline — the laser follows the path, not the stroke width. • All shapes should be closed paths for cut operations. Open paths may cause incomplete cuts. • Ensure no overlapping paths on cut layers — overlapping cuts waste material and may cause burning.
For engraved areas: fills define the engrave region. Use a flat black fill with no stroke. The laser engraves the entire filled area at the configured power and speed.
Importing SVG into LightBurn: File > Import, select the SVG. Each SVG layer or colour group maps to a LightBurn layer. Assign power and speed settings per layer for cut, score, and engrave operations separately.