Laser Settings for Acrylic: Cutting & Engraving Guide
Acrylic is one of the most popular materials for laser cutting and engraving — it produces stunning results when dialed in correctly. However, acrylic introduces variables that other materials don’t: clear vs colored, cast vs extruded, and major differences between CO2 and diode lasers. This guide provides tested starting settings and practical tips so you can get clean cuts and crisp engravings on your first attempt.
Important: CO2 vs Diode Lasers for Acrylic
Diode lasers cannot cut clear acrylic.
The 445 nm wavelength of diode lasers passes straight through transparent acrylic without being absorbed. You must use a CO2 laser (10.6 μm wavelength) for clear acrylic. Colored and dark acrylic absorbs the diode wavelength and can be cut successfully.
CO2 Lasers
- Excellent for both cutting and engraving all acrylic types
- 10.6 μm wavelength is well absorbed by acrylic
- Produces flame-polished edges on cast acrylic
- The standard choice for professional acrylic work
Diode Lasers
- Can cut colored/dark acrylic only
- Cannot cut clear or light-colored acrylic
- 445 nm wavelength passes through transparent material
- Good option if you only work with colored acrylic
Diode Laser Settings for Acrylic
Colored acrylic only. These settings are starting points for 3 mm colored/dark acrylic.
| Machine | Material | Thickness | Speed (mm/s) | Power | Passes | Operation |
|---|---|---|---|---|---|---|
| xTool S1 20W | Acrylic (colored) | 3 mm | 200 | 90% | 2 | Cut |
| xTool D1 Pro 20W | Acrylic (colored) | 3 mm | 200 | 85% | 2 | Cut |
| xTool D1 Pro 10W | Acrylic (colored) | 3 mm | 150 | 100% | 3 | Cut |
| xTool S1 40W | Acrylic (colored) | 3 mm | 300 | 75% | 1 | Cut |
| Sculpfun S30 Pro Max 20W | Acrylic (colored) | 3 mm | 180 | 95% | 2 | Cut |
| Sculpfun SF-A9 40W | Acrylic (colored) | 3 mm | 300 | 70% | 1 | Cut |
| Atomstack X20 Pro 20W | Acrylic (colored) | 3 mm | 200 | 90% | 2 | Cut |
| Creality Falcon 2 22W | Acrylic (colored) | 3 mm | 200 | 90% | 2 | Cut |
| LONGER Ray5 20W | Acrylic (colored) | 3 mm | 190 | 90% | 2 | Cut |
| Ortur Laser Master 3 10W | Acrylic (colored) | 3 mm | 150 | 100% | 3 | Cut |
| TwoTrees TS2 10W | Acrylic (colored) | 3 mm | 150 | 100% | 3 | Cut |
CO2 Laser Settings for Acrylic
CO2 lasers work with all acrylic types including clear, colored, and fluorescent.
| Machine | Material | Thickness | Speed (mm/s) | Power | Passes | Operation |
|---|---|---|---|---|---|---|
| OMTech 40W CO2 | Acrylic (colored) | 3 mm | 15 | 60% | 1 | Cut |
| OMTech 40W CO2 | Acrylic (clear) | 3 mm | 15 | 55% | 1 | Cut |
| OMTech 50W CO2 | Acrylic (colored) | 3 mm | 18 | 50% | 1 | Cut |
| OMTech 50W CO2 | Acrylic (clear) | 3 mm | 18 | 45% | 1 | Cut |
Tips for Laser Cutting Acrylic
- 1Remove the protective film before cutting, or leave it only on the back side. Film on top can cause charring and residue.
- 2Use air assist at LOW pressure. High-pressure air can cool the acrylic too quickly, causing cracking or rough edges.
- 3CO2 lasers produce flame-polished edges on cast acrylic — one of the best features of laser-cut acrylic.
- 4For thick acrylic (6 mm+), multiple slow passes at moderate power will outperform a single aggressive pass.
- 5Keep your work area well ventilated. Acrylic fumes contain MMA (methyl methacrylate) and should not be inhaled.
Tips for Laser Engraving Acrylic
- 1Engrave from the back for a clean, frosted look. Mirror/reverse your design before sending it to the laser.
- 2Apply masking tape on the engraving surface to prevent smoke residue from staining the acrylic.
- 3Use low power and high speed for fine detail. Acrylic engraves cleanly and doesn’t need heavy passes.
- 4Paint-fill your engravings for contrast. Apply acrylic paint over the engraved area, then wipe the surface clean for a professional look.
Cast vs Extruded Acrylic
Not all acrylic is created equal. The manufacturing process matters significantly for laser results.
| Property | Cast Acrylic | Extruded Acrylic |
|---|---|---|
| Price | More expensive | Cheaper |
| Edge quality | Flame-polished, crystal clear | Can bubble or appear gummy |
| Thickness consistency | Very consistent | Can vary across the sheet |
| Laser cutting | Excellent results | Acceptable, edges less clean |
| Laser engraving | Crisp white frost | Can look inconsistent |
| Best for | Signage, awards, display pieces | Prototyping, budget projects |
Can a Diode Laser Cut Clear Acrylic?
Short answer: No.
Clear acrylic is transparent to the 445 nm wavelength used by diode lasers. The beam passes through the material without transferring enough energy to cut. You need a CO2 laser operating at 10.6 μm, which acrylic absorbs readily.
Why this happens: Diode lasers emit visible blue/violet light. Clear acrylic is designed to transmit visible light, so the beam has nothing to interact with. CO2 lasers emit far-infrared light at a wavelength that acrylic absorbs almost completely.
The painting workaround: Some users try painting clear acrylic black to absorb the diode wavelength. While this can technically start a cut, the results are poor — uneven edges, charring, and inconsistent depth. It is not a practical solution for production work.
Colored acrylic works fine: If your acrylic is dark, opaque, or heavily pigmented, a diode laser can cut it successfully. Black, dark blue, red, and other saturated colors absorb the 445 nm wavelength well.
Do NOT laser these materials — toxic fumes
- ×PVC / vinyl — releases chlorine gas (hydrochloric acid)
- ×Chrome-tanned leather — releases hexavalent chromium (carcinogen)
- ×Polycarbonate (Lexan) — produces bisphenol A fumes and discolors badly
- ×ABS plastic — emits hydrogen cyanide when laser cut
Always verify your material before cutting. When in doubt, check the MSDS sheet or ask your supplier.
Troubleshooting
White residue on edges
Cause: Speed too slow or power too high, causing excess heat buildup.
Fix: Increase speed slightly or reduce power by 5–10%. Ensure air assist is running.
Cracking during or after cutting
Cause: Thermal stress from too much heat concentrated in one area.
Fix: Use lower power with multiple passes. Ensure acrylic is flat and unclamped at edges.
Not cutting through
Cause: Insufficient power, incorrect focus distance, or dirty lens.
Fix: Check and clean your lens, verify focus height, add another pass or increase power.
Melted or gummy edges
Cause: Likely extruded acrylic, or too much heat with too little airflow.
Fix: Switch to cast acrylic for better edge results. Reduce power and increase air assist slightly.
What the Research Says
Key findings from peer-reviewed studies on laser cutting PMMA / acrylic.
Kerf Width & Surface Roughness
A Taguchi L18 study on CO2-cut PMMA measured minimum kerf width of 0.3167 mm (at 100W, 20 mm/s, 0.5 bar gas pressure) with surface roughness Ra 0.5–3.0 μm and heat-affected zone depth of 0.12–0.37 mm. Kerf taper was reduced from 1.92° to just 0.02° under optimised conditions.
Khoshaim et al., J. Materials Research & Technology, 2021
Optimal Speed–Power Trade-off
Four metaheuristic algorithms (GA, PSO, WOA, ALO) converged on cutting speeds of 4–7 mm/s at ≤60W with focal plane at centre position for best edge quality. Laser speed is the single most influential parameter for both surface roughness and dimensional accuracy.
Arabian J. Science & Engineering, 2024
RSM-Optimised CO2 Parameters
Response Surface Methodology identified optimal CO2 settings for 4 mm PMMA as 90W / 10 mm/min / 5 mm nozzle distance. PMMA produced less HAZ than polycarbonate and polypropylene, resulting in higher cut quality among common thermoplastics.
Int. J. Interactive Design & Manufacturing, 2025
Key Relationships
Across studies, kerf width widens with higher power and stand-off distance, and narrows with faster cutting speed. The practical rule: low power + high speed = best surface quality and smallest HAZ. Gas pressure has minimal effect on kerf width compared to speed and power.
Synthesised from Khoshaim 2021, AJSE 2024, IJIDeM 2025
Frequently Asked Questions
Can I laser cut clear acrylic with a diode laser?▾
What speed and power should I use for 3 mm acrylic?▾
Why does my acrylic crack when laser cutting?▾
Cast vs extruded acrylic for laser cutting?▾
Do I need air assist for cutting acrylic?▾
How do I get flame-polished edges on acrylic?▾
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