What Speed and Power Should I Use? Let LightBurn's Material Test Tell You
There's no universal settings chart that works for every laser and every board. LightBurn's built-in Material Test burns a grid of settings so you can pick the best one for your machine and material.
“What speed and power should I use?” is one of the questions new laser owners ask most. The honest answer is that it depends on your laser, your material and even the particular board in front of you, which is why a settings list from someone else’s machine often disappoints. LightBurn’s documentation points beginners to a better approach: run a Material Test and let your own machine show you.
What the Material Test does
The Material Test, found under Laser Tools → Material Test, burns a grid of small boxes. Each row and column uses a different value, so one run shows you many combinations side by side. By default it’s a 10 x 10 grid varying speed and power, with the values printed along the edges so you can tell which box is which.
You can also choose to vary other settings, such as line interval or number of passes. LightBurn includes ready-made engrave and cut presets for diode and CO2 lasers as a starting point.
Running your first test
Following LightBurn’s getting-started guide:
- Put down a spare piece of the exact material you plan to use. Settings change from material to material, so test again whenever you switch.
- Focus the laser as your machine’s manual describes.
- In the Laser window, set Start From to Current Position and choose the center dot, then move the head over your scrap. The default grid is roughly 80 x 95 mm.
- Open Laser Tools → Material Test and choose the Engrave preset for your laser type.
- Click Frame to check the grid fits on the material, then Start.
The boxes run from the gentlest settings to the strongest, so the boxes most likely to scorch or flare up come last. Stay with the machine the whole time, have fire suppression on hand, and wear the eye protection your laser’s maker specifies.
Reading the results
- For engraving, pick the box that looks best to you.
- For cutting (run the Cut preset on fresh material), pick the box that cuts through cleanly with the least charring. If several look the same, choose the fastest one.
- If no box cuts through, LightBurn suggests rerunning the cut test with passes in place of power. If nothing cuts after that either, your laser probably can’t cut that material.
Then apply those numbers to a Fill layer for engraving or a Line layer for cutting, or save them in LightBurn’s Material Library so you don’t have to test that material again.
One setting to double-check first
LightBurn’s documentation warns to check your speed units. A speed in millimeters per second is much faster than the same number in millimeters per minute, and mixing them up can leave you with far too little power, or far too much and a fire risk. You’ll find the units setting under Device Settings.