Laser settings by material
Five materials, each with its own safety, chemistry, prep and the settings makers publish. Every number is a maker’s starting point, and the differences between machines are put on one scale: J/mm, the light energy per millimetre of line.
Slate
Pale marks on dark stone. Engrave only — no slate row in maker tables.
See settings →Anodized aluminum
White marks on dyed oxide. Bare aluminum bounces the blue light.
See settings →Leather
Veg-tan only. Chrome-tan is avoided; PVC faux leather never.
See settings →Acrylic
Cast frosts, extruded stays clear. Blue light passes through clear sheet.
See settings →Plywood & basswood
Glue lines decide the cut. Phenolic stalls; interior glue goes through.
See settings →The five materials side by side
Verdicts come from our diode vs CO2 vs fiber matrix; J/mm is the median of the maker’s diode rows (identical LightBurn and LaserGRBL rows counted once, rows that look like typos left out). Cutting energy depends heavily on thickness, so read it as an order of magnitude.
| Material | Blue diode | CO2 | Fiber | Engrave median (diode) | Cut median (diode) | Maker rows |
|---|---|---|---|---|---|---|
| Slate | Engraves | Engraves | Split | 0.084 J/mm | — | 22 rows |
| Anodized aluminum | Engraves | Engraves | Marks | 0.24 J/mm | — | 31 rows |
| Leather | Cuts | Cuts | Split | 0.07 J/mm | 2.9 J/mm | 41 rows |
| Dark or opaque acrylic | Cuts | Cuts | Marks | 0.082 J/mm | 23 J/mm | 65 rows |
| Clear acrylic | Not suited | Cuts | Not suited | — | — | — |
| Plywood & basswood | Cuts | Cuts | Not suited | 0.058 J/mm | 8.6 J/mm | 57 rows |
Whatever the material, start with a test
- Know the material. If you cannot find out what it is, do not laser it (what not to laser cut).
- Pick a nearby row. Choose a maker row for the same laser type and a similar optical power.
- Scale it to your power. The power & speed converter finds the speed or power that gives the same J/mm. Every material page opens it with a row filled in.
- Burn a grid. Run LightBurn’s Material Test (power against speed) on scrap. In LaserGRBL, check the S-value maximum ($30) first.
- Stay with it. Watch every test, with extraction on and the right goggles.
FAQ
- Where can I find laser settings for a material?
- Maker tables are the most reliable starting point. AtomStack publishes LightBurn and LaserGRBL tables for each machine, and TwoTrees publishes a material test list. Our material pages put those rows on one J/mm scale and link each one to the converter so you can scale it to your machine.
- Can I use another machine’s settings directly?
- Not as they are. Power % is relative to each machine, so the same percentage on a different optical power gives a different energy. Between lasers of the same type, matching J/mm gets you close, but focus and spot size still change the result, so always test.
- Which materials can a diode laser not process?
- A blue diode cannot cut clear, white or some blue acrylic, cannot mark glass without a coating, and is listed as not suited to bare brass or copper. PVC, vinyl and faux leather are banned on every laser because they release toxic gas.
- What is J/mm?
- It is the light energy the beam puts into each millimetre of line: optical W × power % × passes ÷ speed in mm/s. It is a common scale for comparing or moving settings between machines of different power. For fill engraving, dividing by the line interval gives J/mm².
Sources
- AtomStack, Material Setting (LightBurn, LaserGRBL and machine tables)
- TwoTrees, Laser Engraver Material Test List
- LightBurn documentation, Material Test
- LaserGRBL, Target image size and laser options (S-MIN / S-MAX)
Last checked 2026-11-01 · Maker values and calculations; we did not process these materials ourselves.