Home › Calculators › Laser test grid generator
Laser test grid generator
A test grid is the fastest way to find real settings for a material, and drawing one by hand is the slowest. This builds the file: one square per setting, each on its own colour so your software puts it on its own layer, sized to fit your bed.
How to run it
Every square comes out on its own colour. LightBurn turns each distinct colour into its own layer, so once the file is open you set one speed and one power per layer and press start — which is the whole point. Doing it by hand means drawing thirty squares and keeping track of which is which, and that is where test grids usually go wrong.
- Generate and download the SVG.
- Import it into LightBurn (or your own software) and check the size is unchanged.
- Work down the legend below and set each layer to its speed and power. The legend order matches the colour order in the file.
- Cut it on the same material, from the same sheet, at the same focus you will use for the real job.
- Mark the winner on the offcut in pencil and keep it.
Reading the result honestly
The square you want is not the darkest or the fastest. It is the slowest-power, fastest-speed square that still does the job cleanly — because every step past that is heat you are putting into the material for nothing, and heat is what causes charring, flashback and warped acrylic.
- Cutting: the winner is the fastest square that separates cleanly when you flex the sheet. If several do, take the fastest.
- Engraving: judge contrast, not depth. A deeper engrave that looks the same is wasted time.
- If every square cuts, your range was too gentle. Regenerate with a faster maximum speed.
- If none do, the problem is usually focus or air assist rather than settings. Check focus before widening the range.
Grids are capped at 30 squares because that is how many layers LightBurn gives you. If you need a wider sweep, run two grids rather than one oversized one — you will read them more reliably anyway.
Why the same grid on two machines gives different answers
Settings do not travel between machines unchanged. If you are bringing numbers over from a different laser, run them through the settings converter first to get a sensible centre for the grid, then let the grid do the fine tuning. The background to all of this is in how to run a laser material test grid.
FAQ
How does a laser test grid work?
You cut a grid of identical squares, each at a different speed and power, on the material you actually plan to use. Comparing the squares side by side on one piece removes the guesswork of changing one setting at a time across several test pieces.
Why is every square a different colour?
LightBurn maps each distinct colour in an imported file to its own layer, and you set speed and power per layer. One colour per square means you can assign thirty different settings in one job. The colours match LightBurn's default palette so they land on layers C00 to C29 in order.
Why is the grid limited to 30 squares?
That is how many layers LightBurn provides. A grid larger than that cannot have one setting per square. If you need a wider sweep, run two grids - you will read them more reliably than one oversized one anyway.
Which square is the right setting?
The fastest, lowest-power square that still does the job cleanly. Every step past that is heat going into the material for no benefit, and excess heat is what causes charring, flashback marks and warped acrylic.