How do you run a LightBurn material test without wasting stock?
‘Just run a material test’ is the standard advice. It’s also how you burn through a $25 tumbler and still don’t know where to start. Steve Makes Everything’s fix for the LightBurn material test: start wide, throw out the cells that are obviously wrong, and run it again on what’s left.
Applies to
- Process
- CO₂, diode & fiber/galvo lasers in LightBurn
- When
- A brand-new material with no known settings
- Steve’s example
- 3 mm matte acrylic, 60 W ComMarker MOPA galvo
Why it matters
Starting in the middle and hoping is a coin flip. One giant grid either has too few useful cells or eats the whole sheet.
Narrowing gets there with small tests. Each round shows you which corners of the grid are junk, so the next round spends every cell where the answer actually is.
Steve’s acrylic run: round one, the 100 mm/s row bubbled, speeds above 700 added nothing, and 10% barely showed. Round two (20% minimum, 700 max): nothing useful past 500 mm/s or under 40%. Round three (40% minimum, 500 max): about 300 mm/s at 75% looked right.
Three small tests. Done.
What good looks like
- Each round’s range is tighter than the last
- You can say why you cut each part of the range: bubbled, invisible, no change
- The final setting is confirmed on a real image, not just a square
- The result goes straight into your settings library
How to apply it
- Open LightBurn’s Material Test and run the default range: 100–1,000 mm/s, 10–100% power.
- Find the dead zones: cells that bubbled or melted, cells too faint to see, and speeds where going faster stops changing anything.
- Raise the minimum power and lower the maximum speed to cut those out. Run it again.
- Repeat until a cell clearly wins. Steve needed three rounds.
- On a MOPA fiber, now test frequency and pulse width at that speed and power.
- Engrave a real image to confirm, then save it to your library.
Test it on your setup
- Before you call it done, engrave something with fine detail. Steve runs a simple octopus, then a detailed clown. If it holds up on detail, it’ll hold up on your job.
Exceptions & tradeoffs
On a diode, speed and power are basically the whole job. Line interval also shifts brightness, but Steve treats that as a per-job tweak, not a material setting.
Mind you, if round one shows nothing usable anywhere on the grid, check the machine before narrowing anything: focus, power scaling, clean optics.
Common mistakes
- Starting in the middle of the range and hopingStart wide on purpose, then narrow
- Running one huge, dense grid on expensive stockRun small grids and narrow between rounds
- Calling it done off a square that looks goodConfirm on a detailed image before you save it
Frequently asked questions
- How do I run a material test in LightBurn?Open the Material Test tool, pick the two parameters (speed and power to start), set their ranges and grid size, and run it on a scrap of your material. The defaults sweep 100–1,000 mm/s and 10–100% power.
- What settings should I start with for a new laser material?Start wide, not in the middle. Run the full default range, cut out the cells that bubble or barely show, and re-run on what’s left.
- How many material tests do I need for a new material?Usually two or three narrowing rounds. Steve Makes Everything found his 3 mm acrylic setting in three.
- Can the LightBurn material test vary something other than speed and power?Yes. You can swap the parameters, for example to frequency and Q pulse on a fiber laser, with speed and power held fixed.
Why online settings and ‘just run a test’ leave you guessing and wasting material — Your Laser Settings Are a Hot Mess! Here's the Quick Fix! ↗ at 00:37.
Round one at LightBurn’s defaults and how he read the dead zones — Your Laser Settings Are a Hot Mess! Here's the Quick Fix! ↗ at 02:45.
Rounds two and three, landing near 300 mm/s and 75% on matte acrylic — Your Laser Settings Are a Hot Mess! Here's the Quick Fix! ↗ at 03:34.
Confirming the setting on an octopus and a detailed clown image — Your Laser Settings Are a Hot Mess! Here's the Quick Fix! ↗ at 06:22.
This is Steve Makes Everything’s workflow start to finish, acrylic numbers included. He ran it on a 60 W ComMarker MOPA galvo; the speed and power narrowing works the same on any laser. The ‘check the machine first’ note is mine.