Home › Guides › Laser settings for acrylic (engraving & cutting)
Laser engraving settings for acrylic
Acrylic is one of the best materials a CO2 laser can run — it cuts with a flame-polished, glass-clear edge. But there's one rule that trips people up: a diode laser cannot cut clear acrylic at all.
Quick answer: engrave acrylic on a CO2 laser at around 20% power / 300 mm/s / 300 DPI, using cast (not extruded) acrylic for a bright, frosted-white mark. For cutting, 3 mm acrylic needs about 55–70% power at 10–18 mm/s depending on wattage, in a single pass. A diode laser can only mark or slowly cut dark, opaque acrylic — clear acrylic needs a CO2 laser.
Price an acrylic job →First: diode vs CO2 on acrylic
Clear acrylic is transparent to a diode laser's ~450 nm blue beam — the light passes straight through and nothing happens. Diodes can only cut dark/opaque acrylic, and even then poorly. For clear acrylic, and for a polished edge, you need a CO2 laser (10,600 nm), which acrylic absorbs beautifully.
Cutting settings — CO2
| Thickness | 40–60 W CO2 | 80–100 W CO2 |
|---|---|---|
| 3 mm | 70% / 10 mm/s / 1 | 55% / 18 mm/s / 1 |
| 5 mm | 85% / 6 mm/s / 1 | 65% / 11 mm/s / 1 |
| 10 mm | 95% / 3 mm/s / 1 | 80% / 5 mm/s / 1 |
For a glossy, flame-polished edge: one slow pass beats several fast ones, and use low air-assist pressure. A hard blast of air frosts the cut edge; a gentle flow keeps it clear.
Engraving settings — CO2
Acrylic engraves as a frosted-white mark on clear, or a contrasting mark on cast colour. Cast acrylic gives a bright frosted engrave; extruded acrylic engraves shallow and dull — buy cast for engraving.
- Typical engrave: ~20% power / ~300 mm/s / ~300 DPI on an 80 W CO2. Lower power + higher speed = frostier white.
- Engrave with the protective film on to keep the surface clean, then peel.
- For a deep, tactile engrave, drop the speed rather than pushing power to 100%.
Safety — read this
Only cut cast or extruded acrylic (PMMA). Never cut polycarbonate (Lexan) — it barely cuts, yellows, and releases harmful fumes. If you're unsure which plastic you have, don't put it in the laser.
Cost it in one step
Acrylic cuts slower than plywood, so time — and price — climbs with thickness. Drop your file into the calculator, choose acrylic and your CO2 machine, and get the cutting time and cost.
Open the calculator →All of these charts in one printable book: The Laser Settings Handbook — 18 machines, 11 material charts, the 15 fixes and a settings log in 168 pages. Read the free 13-page sample.
FAQ
Can a diode laser cut clear acrylic?
No. Clear acrylic is transparent to a diode's ~450 nm beam, so the light passes straight through. Diodes can only mark or slowly cut dark, opaque acrylic. For clear acrylic you need a CO2 laser.
What settings cut 3 mm acrylic?
On an 80–100 W CO2, about 55% power at ~18 mm/s in a single pass. On a 40–60 W CO2, around 70% at ~10 mm/s. Use one slow pass with gentle air assist for the clearest, flame-polished edge.
Why is my acrylic edge frosted instead of glossy?
Too much air-assist pressure or multiple fast passes. Use low air pressure and a single slower pass so the edge melts smooth. Also make sure you're using cast acrylic — extruded engraves and finishes duller.
What's the difference between cast and extruded acrylic for lasers?
Cast acrylic engraves to a bright frosted white and is best for engraving. Extruded acrylic is cheaper and can give a slightly cleaner cut edge but engraves shallow and dull. For most laser work, buy cast.
What are the settings for laser engraving acrylic?
On an 80 W CO2, start around 20% power / 300 mm/s / 300 DPI on cast acrylic for a bright frosted-white mark. Lower power and higher speed gives a frostier result; slow the speed rather than raising power to 100% for a deeper, more tactile engrave.
Is cast or extruded acrylic better for laser engraving?
Cast acrylic. It engraves to a bright, frosted white mark, while extruded acrylic engraves shallow and dull because of how the material is manufactured. Extruded can give a slightly cleaner cut edge, but for engraving, buy cast.