Material
Laser Engraving Acrylic (opaque/black): Diode Settings by Machine
Black and opaque acrylic engrave and cut on a diode laser. Clear and blue acrylic don't; the beam passes through.
How a diode laser handles acrylic (opaque/black)
A blue diode only works on acrylic that absorbs blue light. Black and dark opaque sheets cut cleanly in several passes and engrave to a matte, lighter surface. Clear, translucent and blue acrylic let the beam through. Cast acrylic engraves frostier than extruded; extruded cuts with slightly cleaner edges.
Before you start
- Leave the protective film on while cutting to prevent scorch marks, then peel it
- Make sure the sheet is acrylic (PMMA), not polycarbonate or PVC, which must never be lasered
- Use air assist and a honeycomb bed; molten edges stick to flat surfaces
Starting points, not gospel. Rows marked “starting point” come from manufacturer tables and community results. Run a small power/speed test grid on your own sheet before a real job — batch, humidity and focus all shift the result.
| Module | Job | Thickness | Power | Speed | Passes | LPI | Air | Status |
|---|---|---|---|---|---|---|---|---|
| 10W | EngraveOpaque/black acrylic only — clear acrylic passes 455nm light | 3 mm | 30% | 3000 mm/min | 1 | — | — | Starting point |
| 10W | Cut | 3 mm | 100% | 150 mm/min | 4 | — | On | Starting point |
| 20W | Cut | 3 mm | 100% | 300 mm/min | 2 | — | On | Starting point |
| 20W | Cut | 3 mm | 100% | 250 mm/min | 2 | — | On | Starting point |
| 10W | Cut | 3 mm | 100% | 120 mm/min | 4 | — | On | Starting point |
| 22W | Cut | 3 mm | 100% | 300 mm/min | 2 | — | On | Starting point |
| 20W | Cut | 3 mm | 100% | 250 mm/min | 2 | — | On | Starting point |
Tips
- Several faster passes give cleaner edges than one slow pass, which melts and bubbles
- Keep a small gap between parts so heat doesn't warp thin pieces
- For edge-lit signs, engrave the back of painted clear acrylic instead of trying to cut clear sheet
Frequently asked questions
Can a diode laser cut clear acrylic?
No. The blue beam passes through clear and most translucent acrylic. Use black or opaque colours, or a CO2 laser for clear.
Why are my acrylic edges bubbly?
Too much heat in one place: the single pass is too slow. Raise the speed and add passes, and keep air assist on.