Importing SVG into LightBurn Without Losing Scale or Layers

LightBurn reads SVG geometry accurately but ignores most presentation styling, CSS, and effects. The two problems that surface most often are incorrect scale on import (a 100mm design arrives at 264mm) and lost layer structure (all paths land on one layer or colors do not map as expected). Both are fixable once you understand how LightBurn interprets SVG units and color-to-layer assignment.

What LightBurn Reads and What It Ignores

LightBurn imports path geometry — lines, polylines, curves, rectangles, circles, ellipses, and polygons — but strips most styling. Fill colors, gradients, stroke widths, patterns, shadows, and blur effects do not transfer. Text is imported as paths if you convert it to outlines first; otherwise it is ignored. Clipping masks, layer blend modes, and opacity are also discarded.

The import dialog offers a color-to-layer mapping step. Each unique stroke or fill color in the SVG becomes a selectable item in the dialog, and you assign each color to a LightBurn layer. This is your opportunity to organize cuts, engraves, and scores by color. If your SVG has no color differentiation (everything is black), all paths will merge onto a single layer and you will have to manually reassign them after import.

The Scale Problem: SVG Pixels vs Real-World Units

This is the most common LightBurn import complaint. You design a 100mm part in Inkscape or Illustrator, export to SVG, import to LightBurn, and it measures 264mm. The cause: SVG defaults to pixels (px) as its unit, and LightBurn interprets px at 96 PPI (pixels per inch), which is the web standard but not a CAD standard.

When your design software saves an SVG, it often omits explicit units on the root width and height attributes, writing width="1000" instead of width="100mm". LightBurn sees 1000 with no unit and treats it as 1000 px. At 96 px/inch, 1000 px = 1000 ÷ 96 = 10.417 inches = 264.58 mm. Your 100mm design is now 2.6× too large.

Fix 1: Set Units in Your Design Software Before Export

In Inkscape, set the document units to millimeters in File → Document Properties → Display Units. Ensure the page size is set in mm and that objects are drawn using mm as the grid unit. When you export to Plain SVG, Inkscape will embed width="100mm" in the SVG, and LightBurn will import it at the correct scale.

In Illustrator, set the document units to millimeters in File → Document Setup. When saving as SVG, choose File → Export → Export As and select SVG. In the SVG Options dialog, set CSS Properties: Presentation Attributes and Decimal Places: 3. Illustrator will write the units explicitly.

Fix 2: Scale After Import in LightBurn

If the SVG is already saved without units, you can fix the scale in LightBurn after import. Select all imported objects (Ctrl+A or Cmd+A), then use Edit → Scale or the numeric scale fields in the toolbar. Measure one known dimension (e.g., a 100mm edge) and calculate the correction factor. In the 1000px example above, the correction is 100 ÷ 264.58 ≈ 0.378. Apply that scale to all objects.

Alternatively, you can configure the import scale in LightBurn's File → Import dialog. Before finalizing the import, look for a "Scale" or "Units" option. Some versions of LightBurn allow you to specify a unit override (mm, inches, cm). Set it to match your design intent, and the scale will apply automatically.

Layer Assignment and Color Mapping

When you import an SVG, LightBurn scans for unique colors and presents them in the import dialog. Each color becomes a row with a checkbox and a layer dropdown. Check the colors you want to import and assign each to a LightBurn layer (C00, C01, etc.). Unchecked colors are discarded.

If your SVG uses black for everything, all paths will map to one layer. You can split them after import by selecting paths and reassigning them to different layers in the Cuts / Layers panel. Right-click a path, choose Move to Layer, and select the target layer. This is manual but necessary if the source file has no color differentiation.

A better workflow: assign colors in your design software before export. Use one color (e.g., red) for cut lines, another (e.g., blue) for engraves, and a third (e.g., green) for score lines. When you import the SVG, map red to a layer configured for cutting, blue to a layer configured for engraving, etc. This preserves your intent and saves time.

Handling Open vs Closed Paths

LightBurn distinguishes between open and closed paths for fill purposes. A closed path (where the end node connects to the start node) can be filled; an open path cannot. If you import a shape that should be filled (engraved) but it renders as an outline, the path is likely open. Close it in LightBurn with Tools → Close Path, or close it in your design software before export by snapping the final node to the start node.

Text Handling and Font Conversion

LightBurn can import text two ways: as editable text (if you design directly in LightBurn) or as paths (if you convert the text to outlines in your design software first). If you export text from Illustrator or Inkscape without converting to outlines, LightBurn will ignore it because it does not have access to your system fonts.

To preserve text, select it in your design software and convert to paths: Type → Create Outlines in Illustrator, Path → Object to Path in Inkscape. The text becomes a group of filled shapes. When you import the SVG, those shapes will appear as engraveable regions. Assign them to a layer configured for engraving and set the fill mode to Fill in the layer's cut settings.

For workflows that start with raster images, see the PNG to laser-ready vector guide. If you need to optimize file structure before import, the laser cutting file optimization article covers node reduction and path ordering. For kerf compensation, refer to the kerf and press-fit guide.

Troubleshooting Import Failures

If LightBurn fails to import your SVG or the preview is blank, the file likely contains unsupported elements or malformed XML. Open the SVG in a text editor and check for these issues: embedded raster images (base64-encoded PNGs), JavaScript or <script> tags, external stylesheet references, or non-standard XML namespaces.

Remove embedded images and scripts, then re-save the file. In Inkscape, use File → Save a Copy → Plain SVG to strip metadata and unsupported features. In Illustrator, uncheck Preserve Illustrator Editing Capabilities in the SVG export options.

Another common issue: transforms and groups. If an SVG uses transform attributes (translate, rotate, scale) on groups, LightBurn may interpret the geometry incorrectly. Flatten transforms before export by selecting all objects and choosing Object → Transform → Reset or Path → Object to Path. This bakes transforms into the path coordinates.

For more context on how different machines handle SVG and DXF, compare the Glowforge SVG requirements, the Cricut Design Space upload process, and the Silhouette Studio DXF vs SVG differences. Each system has its own quirks, but understanding one helps troubleshoot another.