What size should an SVG be for laser cutting?

Its real physical size, in millimetres. Set the document units to mm and design at the exact size you want to cut, then verify it after import.

Should I convert text to paths before laser cutting?

Yes. Live text depends on installed fonts. Converting to paths freezes the letter shapes, and combining them keeps counters in letters like O and A as real holes.

What stroke width should cut lines have?

A hairline, roughly 0.01 to 0.1 mm. Laser software follows the centre of the path, so the visible width does not change the cut, but a hairline avoids confusion and accidental fills.

Why does my SVG cut the outline twice?

Usually overlapping or duplicated paths, or a shape with both a stroke and a fill that land on two layers. Union overlapping shapes and delete duplicates.

Does an SVG need to be saved as Plain SVG?

It is a good habit in Inkscape, because Plain SVG leaves out editor-specific data that some laser programs misread. It is not required by every program.

How to Prepare an SVG for Laser Cutting: 7-Step Checklist

You press Start, the gantry hums, the first pass smells like warm birch, and thirty seconds later you realise the heart you drew is the size of a coin, the letters are missing their middles, and the outline was cut twice. Every maker has had that moment. Almost all of it is avoidable in ten minutes of SVG preparation for laser cutting before the laser ever moves.

This is the checklist we use on every file we publish. It works for LightBurn, xTool Creative Space, LaserGRBL-friendly workflows and most other laser software, and the examples use Inkscape because it is free.

What a laser-ready SVG looks like

A laser does not care how pretty your artwork is. It follows paths. A good laser SVG therefore has:

a document size in real units (millimetres), so 90 mm means 90 mm;
only paths, no live text, no embedded photos you did not mean to engrave, no filters or gradients;
cut lines as thin strokes in one colour, engraving as solid fills in another;
closed shapes with no duplicate or stacked lines.

For a sense of what the end result should be, open any of our files, for example the reindeer ornament: a red hairline CUT outline, black ENGRAVE fills, 90 × 124 mm, nothing else.

Element	Laser-ready	Not laser-ready
Size	width="90mm" height="124mm" with matching viewBox	800 px wide, no units
Text	Converted to paths	Live font that may be substituted
Cut lines	Hairline stroke, no fill	Thick stroke or filled shape
Engraving	Solid fill, no stroke	Gradient, blur or shadow
Contours	Closed, single line	Open ends, doubled lines

Step 1: Set the document to real size

Open Document Properties (Shift+Ctrl+D in Inkscape) and set the display units and the page size to millimetres. Set the scale to 1 user unit per 1 mm if your version offers it. Then draw or scale your design so its real size is what you want to cut, for example 90 mm wide.

Why this comes first: an SVG with no units is read by different programs at different resolutions (72, 90 or 96 pixels per inch), and that is the number one reason a file arrives at the wrong size. The full story is in why an SVG is the wrong size in LightBurn and how to scale laser files.

Pro tip: draw a 50 × 50 mm square in the corner of your file while you work. After import you can measure it in a second, and you delete it just before the final cut.

Step 2: Convert text and shapes to paths

Live text only looks right on a computer that has the font. Select every text object and use Path > Object to Path (Shift+Ctrl+C in Inkscape). Do the same for rectangles, ellipses and stars so the laser software sees ordinary outlines. If you used strokes as shapes (a thick line to make a bar), use Path > Stroke to Path so the bar becomes a real outline.

Check letters with holes (A, O, R, 8). After converting, the inner counters must be real holes, not black blobs. Select the letter and choose Path > Combine (Ctrl+K) so the counter is cut out of the body.

Step 3: Separate cut and engrave by colour

Most laser programs map each colour to a layer with its own speed and power. Keep the scheme simple and consistent:

Job	Stroke	Fill	Typical layer in software
Cut through	Red, hairline	None	Cut, lowest speed, highest power
Score (line only)	Blue, hairline	None	Line, low power
Engrave	None	Black	Fill / scan, high speed

Never mix: a shape with both a red stroke and a black fill will be sent to two layers and burn twice. If you want an engraved shape with a cut outline, make two copies: one fill-only, one stroke-only. More on this in cut, engrave and score layers and what a hairline stroke is.

Step 4: Close open paths and join the pieces

An open path (one whose ends do not meet) cuts fine, but the part will not drop out cleanly and some software refuses to fill it for engraving. Select the path, switch to the Node tool (N), select the two end nodes and press Shift+J to join them. If the gap is large, draw a segment first.

If your design is made of overlapping shapes, merge them with Path > Union (Ctrl++). Overlapping outlines mean the laser traces the same edge twice, leaving a darker, wider burn. For files that came from DXF, the full repair routine is in fixing open contours and double lines.

Common mistake: exporting the SVG with a transparent white rectangle behind the design. The laser software sees a rectangle as a cut path and obediently cuts the whole sheet outline, or engraves a solid block. Delete background rectangles before saving.

Step 5: Add features that survive the real world

A pretty outline can still fail on the sheet. Check these before exporting:

Check	Safe minimum (3 mm plywood)	Why
Narrowest bridge or antler tip	2 mm or more	Thinner snaps while you sand or hang it
Distance between a hole and the edge	3 mm or more	Thread tears through thin walls
Hanging hole diameter	3–5 mm	See hanging hole size
Gap between parts that touch	0 mm only if you want a shared line	Otherwise 2–3 mm so the burn does not merge them
Text height for engraving	4–5 mm or taller	Smaller letters fill in with char

Step 6: Save the right way

In Inkscape use Save As > Plain SVG, not Inkscape SVG, so editor-specific extras are left out. Illustrator users should choose SVG with Presentation Attributes or Style Attributes and, importantly, remember that Illustrator measures at 72 dpi, so check the size after import. Keep file names simple: no accents or spaces make life easier for older controllers and cloud software.

Step 7: Test import before you burn

Import the file, select it and read the width and height. They should match your plan. Then check:

Do the layers show up as the colours you set (cut red, engrave black)?
Does the 50 mm test square measure 50 mm?
Run the software's preview or simulation. Is the order sensible, with engraving first and the outer cut last?
Burn one copy on scrap the same thickness as your real material.

Pro tip: engraving first, cutting last. Once the outline is cut, the piece can shift by a fraction of a millimetre and the engraving lands crooked.

Quick troubleshooting

Symptom	Likely cause	Fix
Part is 75% or 133% of expected size	72 vs 96 dpi mismatch	Scale by 133.3% or 75%, or re-export with mm units
Cut line is wide on screen	Thick stroke	Set stroke to hairline, 0.01–0.1 mm
Letters have no holes	Counters not combined	Path > Combine
Everything cuts as one layer	All shapes the same colour	Assign separate colours
Outline burns twice	Duplicate overlapping paths	Union or delete duplicates

Next step

Download a free CC0 ornament, import it, and compare its layers and size with your own file. Copy the setup that worked. When your own file passes the 50 mm square test, you are ready to cut. If you cut flat plywood from a big sheet, a box generator file or a few ornaments from the Christmas category make a cheap first real-world test.