How to Make Laser Cut Files: A Step-by-Step Beginner Guide

If you have a laser cutter and an idea, the gap between the two is a file. Learning how to make laser cut files is mostly about a handful of rules: vector lines, the right colours, the right size, and a little allowance for the material the beam burns away. Once you know them, any drawing program becomes a laser design tool.

What a laser cut file actually is

A laser cutter does not "see" a picture. It follows paths. A laser cut file is a set of instructions that says: move the head along this line, at this power, at this speed.

That is why the file needs to be a vector drawing. A vector is a line defined by points and curves, so it stays sharp at any size and the machine can trace it exactly. A photo (JPG or PNG) is a grid of pixels. It can be engraved, but it cannot be cut, because there is no line to follow.

Most laser files contain three kinds of work:

• Cut lines go all the way through the material.
• Engrave areas are filled shapes or images the laser shades in, line by line.
• Score lines are light marks on the surface, used for fold lines and fine detail.

Your software tells these apart by colour, which is why colour matters so much in laser design. We cover the difference in detail in laser cutting vs engraving vs scoring.

How to make laser cut files: the 7 steps

Here is the full workflow. It works in Inkscape (free), Illustrator, CorelDRAW, Affinity Designer, or straight inside LightBurn.

1. Measure first. Write down the real-world size of your piece and the thickness of the sheet you will cut. Measure the sheet with calipers; "3 mm" plywood is often 2.7 to 3.2 mm.
2. Set your document units to millimetres (or inches, but pick one and stick with it). Set the page to your machine bed size or your sheet size.
3. Draw with shapes, not brushes. Use rectangles, circles, the pen tool and boolean tools (union, difference). Avoid brush strokes and effects, because they often export as filled blobs rather than single lines.
4. Convert everything to paths. Text, shapes and strokes should all become plain paths before export. In Inkscape this is Path > Object to Path; in Illustrator, Type > Create Outlines for text.
5. Colour by operation. A common convention is red for cut, blue for engrave and green for score. Any colours work, as long as each operation has its own.
6. Allow for kerf on any part that has to fit into another, such as tabs, slots and finger joints.
7. Export as SVG or DXF, then import into your laser software and check the size before you press start.

Getting the lines right

Clean lines save more ruined sheets than anything else. Before you export, check for these:

• Hairline strokes. Cut and score lines should be very thin. Many makers use 0.025 mm or 0.1 mm. Some software (notably older Epilog and Trotec print drivers) only treats a line as a vector cut if the stroke is a hairline.
• No fill on cut shapes. A filled red rectangle may be read as an engrave area, not a cut.
• Closed paths. A shape whose start and end points do not meet will leave a small uncut gap, and your part will stay attached.
• No duplicate lines. Two identical lines stacked on top of each other get cut twice. That means extra burning, wider kerf and more charring. LightBurn has Edit > Delete Duplicates for this.

Choosing a file format

For cutting, the two everyday formats are SVG and DXF. SVG keeps colours well and is the native format for Glowforge and xTool Creative Space. DXF comes from the CAD world, is very good at exact geometry, and is accepted by almost every machine. If you want the full comparison, read SVG vs DXF for laser cutting.

LightBurn users can also save .lbrn2 files, which keep power and speed settings with the design. EPS and PDF are useful for print-based workflows and for opening in CorelDRAW or Illustrator. Each has its place, and you rarely need more than two of them.

If drawing every part by hand sounds slow, the Digital Creation laser cut tool builds boxes, trays, signs, coasters, stands and frames from a few measurements and gives you all of these formats in one download.

Allowing for kerf

The laser beam has width. When it cuts, it removes a thin strip of material, usually around 0.1 to 0.3 mm on a CO2 laser. This strip is called the kerf.

For a decoration that does not touch anything, kerf barely matters. For a box with finger joints, it decides whether the joints are tight, loose or impossible to press together. Tabs end up slightly smaller than drawn and slots slightly bigger, so a design drawn at exact size will fit loosely.

The fix is to make tabs a little wider (by about half the kerf on each side) so the parts press together snugly. The exact amount depends on your machine and material, so measure it once with a simple kerf test and write the number down.

A pre-cut checklist

Run through this list before every job.

• Units are millimetres and the design measures the right size after import.
• All text is converted to paths.
• Cut lines are hairlines with no fill.
• Each operation (cut, engrave, score) has its own colour and layer.
• Inner cuts (holes) will be cut before the outer outline. Most laser software does this automatically, but check the cut order setting.
• Paths are closed and there are no duplicates.
• Joints include a kerf allowance that matches your material.
• The design fits on your sheet with a few millimetres of margin.

Common mistakes and how to fix them

The design imports at the wrong size. This usually comes from a mismatch in units or DPI between programs. Check the size right after import and scale to the known dimension. Exporting as plain SVG with millimetre units avoids most of this.

Some lines will not cut. They are probably still text objects, strokes with a fill, or clipped groups. Convert to paths, release clipping masks, and ungroup.

Joints are loose. You drew at nominal size with no kerf allowance, or your sheet is thinner than you designed for. Measure the sheet and adjust.

Edges are badly burned. This is a settings issue, not a file issue, unless you have duplicate lines. Lower power, raise speed, use air assist, and run a material test before the real job.

Start with a test piece

Before cutting a full design, cut one small part, or one corner joint, from the same sheet. It confirms size, settings and fit for the price of a few square centimetres. Laser settings vary a lot between machines, tubes and lenses, so treat any power and speed numbers you find online as a starting point to test, not a recipe.

Always stay with the machine while it runs, keep the extractor on, and have a fire extinguisher within reach.

When you would rather skip the drawing step, the laser cut file maker produces layered, colour-coded files with kerf already allowed for in the joints, ready to check and cut.

Frequently asked questions

What is the best free software to make laser cut files?

Inkscape is the most popular free option. It draws vectors, works in millimetres and exports SVG and DXF. LightBurn is paid but lets you design and run the laser in one program.

Can I make laser cut files from a photo?

You can engrave a photo directly. To cut it, you first need to trace it into vector outlines, using a tool such as Inkscape's Trace Bitmap or LightBurn's Trace Image, and then clean up the result.

What line thickness should laser cut lines be?

Use a hairline, such as 0.025 mm or 0.1 mm. The line thickness in the file does not change the cut width, but some software only treats hairlines as cut lines.

Do I need to add kerf to every design?

No. Only parts that fit into each other, like tabs, slots, inlays and finger joints, need a kerf allowance. Signs, ornaments and coasters can be drawn at exact size.