Here the tracer starts in Black and white with Centre line ticked: instead of outlining the ink, it follows the middle of every line and gives each one as a single stroke. Try the sample drawing, or drop your own line art, lettering or signature.
When a single line beats an outline
A pen plotter, or a laser set to line mode, follows a path. Give it an ordinary traced outline and it runs around both edges of every line, so each stroke is drawn twice and comes out as a hollow double line. A centerline trace gives them the path they actually need: one stroke down the middle, with open ends where the drawn line ends.
How the trace works
- The drawing is split into ink and paper at the threshold, exactly as in the outline trace.
- The ink is thinned, layer by layer from its edges, until every line is one pixel wide, and small staircase corners are tidied away.
- The thin lines are followed from end to end and between the points where lines meet; little whiskers that thinning leaves on thick blobs are pruned.
- Each line is smoothed into curves with the same smoothness setting as outlines.
Getting clean strokes
- Start from lines, not areas. Pen and marker drawings, handwriting, technical drawings and signatures trace well. Solid shapes and bold fills reduce to lines through their middle.
- Keep lines apart. Where two lines touch or cross, they meet at a junction and continue as separate strokes, which a plotter draws one after another.
- Adjust the threshold until thin lines are unbroken in the preview, and raise the smoothness for shaky hand-drawn lines.
- Download DXF for laser and CAD software: every stroke is a polyline on a layer named LINE, open at its ends, closed only for a ring. The SVG uses the same strokes with round ends.