How to prepare artwork for a laser cutter

Draw your cut lines as paths in Vectornation by Zaweba, then choose File > Export > G-code. The export writes instructions for laser cutters, pen plotters and drag knives, in millimetres, cutting holes first, with the speeds, number of passes and laser power you set (or pen heights for a plotter). That file goes straight to the machine's controller.

Laser cutters do not read pictures. They follow a path, moving the head along each line at a set speed and power. G-code is the list of moves the machine follows, so the job of the drawing program is to turn your shapes into a sensible sequence of cuts.

Drawing for a cutter

Work at real size. Set the document up in millimetres at the size of the finished piece, because the export is in mm and the machine will cut exactly what you draw.

Use outlines, not fills. The cutter follows paths, so every edge you want cut must be a path. Text has to be outlined to become paths, and filled shapes should be thought of in terms of their outline. Keep a copy with live text in case the wording changes.

Close your shapes. A gap of a fraction of a millimetre in a shape that should be closed will leave a piece hanging by a thread. Vectornation's path tools, including the Pathfinder and shape builder, help join and tidy outlines before you export.

Remove doubles. Two lines on top of each other get cut twice, which burns the edge. Look for duplicates where shapes meet, especially after combining artwork from different sources.

Why holes come first

The export cuts holes before outer edges. That is the right order for a laser: if the outer edge is cut first, the part can drop or shift slightly in the bed, and any holes cut afterwards end up in the wrong place. Cutting inside shapes first keeps the part held by the sheet until the very last cut.

Speeds, passes and power

Set these to suit your material and machine. Thin card needs a fast speed and low power. Thick plywood may need slower speeds and more than one pass. Running a small test piece in the corner of a sheet is the usual way to find good values, and once you have them, write them down for that material.

If you are driving a pen plotter rather than a laser, the same export uses pen heights instead of laser power, and with a drag knife the paths become the knife's route through vinyl or card.

Measuring before you cut

The Ruler tool shows distance, angle, width and height, and clicking a closed shape gives its area and perimeter. Perimeter is handy for estimating cutting time. The Dimension tool adds linear, angular or radius dimensions to a drawing if you need a dimensioned sheet for a customer to approve before you cut.

Other things to check

Many laser workflows need a little allowance for the width of the beam, so tabs and slots that must fit together may need adjusting. Test a joint before cutting a whole box.

If your cutting software prefers a vector file rather than G-code, Vectornation also saves SVG, DXF and other formats, so you can hand the drawing over in whichever form your machine's own program reads.

Vectornation by Zaweba is free software for Windows, works offline and needs no account, which suits a workshop PC that is not always online.