Why did my thick lines import as thin single lines, and how do I make the line width carve?

Why it happens

In a drawing program a line is a path with a stroke width painted on top. The software imports the path and ignores the paint. That is why the official FAQ tells CorelDRAW users to set line thickness to Hairline and remove fills before exporting: only the geometry matters.

The V-Carve toolpath works out its depth from the width and shape of the vectors, so it needs two edges with a gap between them. A single open line has no width to carve.

Decide first: follow the line, or carve its width

• Follow the line. Keep the single lines and cut along them. The Profile toolpath can run On an open vector, and Quick Engrave has an Outline option. Groove width then comes from the bit and depth.
• Carve the drawn width. Turn each stroke into an outline before export, as below.

Fix it in the drawing program

Illustrator

1. Select the stroked artwork.
2. Choose Object > Path > Outline Stroke.
3. With the result selected choose Object > Compound Path > Make.
4. Where outlined lines cross, use Unite in the Pathfinder panel so overlapping pieces become one path.

Inkscape

1. Select the stroked paths. The stroke width must be above zero.
2. Choose Path > Stroke to Path (Ctrl+Alt+C). The stroke becomes a filled shape made of two parallel edges.

Then export again and import the new file.

Fix it inside the software

If the outlines are already imported but overlap, select them and use Weld Vectors, which treats closed shapes as solid areas and keeps only the outer edge. Then run the Vector Validator with V-Carving Mode checked to mark overlaps, intersections and zero-length spans before you calculate.

Pro tips

• Hairlines are a warning sign. Any stroke that looks thin on screen becomes a very narrow outline, and V-carving it gives a shallow scratch (see the entry on minimum detail size).
• Outlining strokes roughly doubles the node count. Do it on a copy and keep the original line drawing.
• Open shapes will not V-carve or pocket. See the entry on fixing open vectors if the toolpath will not calculate.