Most failed laser jobs do not start at the machine. They start with a DXF that looked fine on screen but was saved in the wrong format, at the wrong scale, or with outlines that do not close. Here is a checklist you can run in a few minutes, whether you are the designer or the shop receiving the file.
DXF exists in two flavours: ASCII (plain text) and binary. Many CAM and laser programs read ASCII DXF reliably, while binary DXF support varies. Open the file in a plain text editor: an ASCII DXF starts with readable lines such as 0, SECTION, 2, HEADER. A binary DXF begins with AutoCAD Binary DXF followed by unreadable characters. If it is binary, re-export and choose ASCII in the save options.
DXF files can be unitless, so a 100 mm part may import as 100 inches or 3.94 mm. Look for the $INSUNITS header value (4 = millimetres, 1 = inches), and measure one known dimension after import. Ask customers to state the intended size of one feature.
An outline with a tiny gap is an open path. Depending on your software, it may cut incompletely, fail to fill, or leave the part attached to the sheet. Use your CAD tool's "join" or "close" command, or select the outline and check it reports as one closed polyline.
Stacked duplicate lines make the laser cut the same edge twice, burning the edge and wasting time. Most CAD and laser programs have a "delete duplicates" or "overkill" function.
Some programs handle splines and text entities poorly. Convert splines to polylines or arcs if your software asks for it, and explode or outline text so it does not depend on a font.
Put cuts, scores and engravings on separate layers or colours, and agree a convention with your customer (for example red = cut, blue = score). Delete construction lines, dimensions and title blocks.
Compare the overall bounding box with your sheet size and machine bed, leaving a margin. Check that small features and gaps are larger than your kerf and material thickness allow.
Very large DXF files usually mean unnecessary detail: thousands of tiny segments, hidden geometry or embedded blocks. Cleaning them speeds up import and cutting.
If you sell laser or CNC work on Shopify and customers upload their own files, CutReady checks supported SVG, ASCII DXF and PDF files on the product page before add-to-cart, with size limits of 256 KB for SVG, 512 KB for ASCII DXF and 2 MiB for PDF. Files that fail are blocked with a clear message so the customer can fix them before ordering. It comes with a 14-day free trial, then 39 USD every 30 days.