Laser Cut Acrylic

Acrylic sheet cutting & material guide: Properties, FAQs, and design tips

When you’re designing parts in acrylic—whether it’s for functional prototypes, consumer products, or creative projects—there are a lot of questions that come up. Acrylic is one of the most versatile plastics available, but it has very specific strengths, weaknesses, and best practices you’ll want to understand. Below you’ll find answers to the most common questions customers ask about acrylic, based on real-world design, fabrication, and application considerations.

Key things to know about Acrylic

Crystal Clarity: Acrylic transmits up to 92% of light, rivaling glass for transparency and aesthetics. Best for Laser Cutting: Cast acrylic cuts cleanly with flame-polished edges and engraves with a frosty-white finish. Strong but Brittle: 10× stronger than glass but more prone to cracking than polycarbonate under impact. Weather-Resistant: Naturally UV-stable, won’t yellow in sunlight, and lasts 10–15 years outdoors. Heat-Sensitive & Flammable: Softens around 160–190°F and is flammable—design accordingly.

1. What’s the difference between cast and extruded acrylic?

One of the first questions people ask is about the difference between cast acrylic and extruded acrylic. They look similar at a glance, but the manufacturing process and resulting performance vary.

• Cast Acrylic is produced by pouring liquid acrylic monomer into molds where it polymerizes. This process results in excellent clarity, a harder surface, and more consistent machining performance. Cast acrylic engraves with a frosty white appearance, which makes it the preferred choice for laser engraving.
• Extruded Acrylic is pushed through rollers and stretched into sheets. It’s cheaper to produce and often more dimensionally consistent across large sheets, but it’s softer and more prone to melting when machined. Laser engraving extruded acrylic often produces a clear, low-contrast mark instead of the crisp frosty look designers want.

For high-precision laser cutting and engraving, cast acrylic is almost always the better choice which is why SendCutSend uses cast acrylic only.

2. How does acrylic compare to polycarbonate?

Acrylic and polycarbonate are frequently compared because they’re both transparent plastics. Here’s how they stack up:

• Clarity: Acrylic has superior optical clarity and light transmission (up to 92%), making it the go-to for applications where aesthetics and transparency matter most. Polycarbonate is clear but has a slight haze or tint.
• Impact Resistance: Polycarbonate is up to 250 times stronger than glass, while acrylic is about 10 times stronger than glass. Acrylic is more rigid and brittle, while polycarbonate can absorb heavy impacts without shattering.
• Heat Resistance: Polycarbonate handles higher service temperatures. Acrylic can start softening around 160–190°F.
• Flammability: Acrylic is more flammable than polycarbonate and will ignite more easily under heat.
• Edge Finish: Acrylic laser cuts beautifully with smooth, flame-polished edges. Polycarbonate tends to discolor, char, or bubble when laser cut.

If your project values clarity and polished edges, acrylic is ideal. If you need impact resistance or heat resistance, polycarbonate may be better.

3. Is acrylic UV-stable outdoors? Will it yellow?

Yes, acrylic is naturally UV-stable. Unlike some plastics, acrylic won’t yellow noticeably in sunlight, even after years of exposure. That’s why acrylic is used in outdoor signage, aquariums, and architectural glazing. However, not all acrylic grades are created equal. Some formulations are more weather-resistant than others. While cast acrylic performs well outdoors, cheap extruded grades may craze or degrade faster. If your project is permanently outdoors, acrylic is usually a safe bet—but if you need maximum weathering resistance, specialty grades like UV-stabilized acrylic sheets may be preferable.

4. When should I cut acrylic at home vs outsourcing to a manufacturer?

The decision comes down to volume, precision, and equipment access.

• Cutting acrylic at home makes sense if:
  • You already own a CO₂ laser cutter or small CNC router.
  • Your parts are simple shapes, prototypes, or one-offs where tolerances aren’t critical.
  • You’re experimenting, learning, or doing hobby projects where surface finish isn’t the top priority.
• Outsourcing to a manufacturer (like SendCutSend) is better when:
  • You need tight tolerances (±.009”), smooth flame-polished edges, or consistent results.
  • Your parts have complex geometries, fine details, or engraving.
  • You’re ordering multiple pieces and want repeatability across all of them.
  • You’d rather not deal with the fumes, ventilation, and safety concerns of cutting acrylic yourself.
  • You want access to multiple colors, finishes, and materials without stocking them yourself.

In short: if your project demands professional results and production-quality consistency, outsourcing is the more efficient and cost-effective route. If you’re tinkering or testing ideas, cutting at home can be a fun way to learn—but it won’t match the precision or scalability of professional fabrication. If you’re ready to get acrylic parts cut at SendCutSend, review our design guidelines for the best results. 

5. Should I remove masking before laser cutting?

Most acrylic sheets come with protective masking on both sides to prevent scratching during handling. When laser cutting, it’s generally best to leave the masking on—especially if it’s paper-based.

• Paper masking absorbs the heat and prevents surface marks from smoke or flashback during cutting.
• Plastic masking can melt and cause flare-ups, so it’s less desirable for laser processing.

At SendCutSend, we cut acrylic with the correct settings so masking doesn’t interfere with precision. Keeping masking in place until you’re ready to use the part ensures you receive scratch-free, polished components.

6. Can you laser cut clear acrylic with a fiber laser?

This is a big question. Traditionally, CO₂ lasers are used to cut acrylic, because their 10.6 µm wavelength is strongly absorbed by the plastic. Fiber lasers, however, operate at around 1.06 µm—wavelengths that clear acrylic naturally transmits. That means clear acrylic doesn’t absorb fiber laser energy efficiently and can be very difficult to cut. SendCutSend uses advanced laser setups to process acrylic, but in general, if you’re cutting acrylic yourself, CO₂ lasers are the preferred method. Fiber lasers are much better suited to metals.

7. Are there fumes or emissions when laser cutting acrylic?

Yes, acrylic does release emissions when laser cut but compared to some plastics, they’re relatively manageable. When cut, acrylic produces fumes that are primarily methyl methacrylate monomer (MMA) vapor. These fumes have a strong odor but are not as toxic as PVC or polycarbonate fumes. Still, you must use proper ventilation and exhaust systems when laser cutting acrylic. Good airflow keeps cuts clean and ensures operator safety. At SendCutSend, our industrial exhaust systems handle this automatically so the end user only receives clean, safe acrylic parts.

8. What kerf allowance and tolerances should I design for?

Laser cutting always removes a small amount of material—this is called the kerf. With acrylic, kerf width is influenced by laser power, focus, and material thickness. At SendCutSend, our acrylic cutting tolerance is ±.009”. That means if you need parts to press-fit together, you’ll want to account for kerf when designing slots, tabs, or interlocking features. As a rule of thumb:

• Leave at least .006–.010” clearance for slip fits.
• Leave negative clearance (slightly smaller slot width) for tight press fits, depending on thickness.
• Keep fine details like slots or cutouts larger than the laser’s kerf for consistent results.

9. How close can holes or features be to the edge?

Because acrylic is rigid but brittle, placing holes or slots too close to the edge can create stress points that lead to cracking.

• A good guideline is to leave at least 1.5x the material thickness between a hole and the nearest edge.
• For thicker acrylic, you can sometimes go closer, but keep in mind that sharp stress points will always reduce durability.

Adding corner fillets and rounding edges near holes can improve crack resistance significantly.

10. Should I add fillets to internal corners?

Yes. Fillets (rounded corners) are highly recommended when designing acrylic parts. Sharp internal corners concentrate stress, which can cause cracks to propagate under load. By adding even a small radius (e.g., 0.02”–0.05”), you spread the stress more evenly. This makes your acrylic part more durable and less prone to fracture during use or assembly. This design-for-manufacturing step costs nothing in CAD but can extend the service life of your part.

11. Can I tap threads in acrylic?

It is possible to cut threads in acrylic, but it must be done carefully:

• Use sharp taps designed for plastics.
• Go slowly, apply very light pressure, and back the tap out frequently to clear chips.
• Avoid fine-pitch threads; use coarser threads where possible.

That said, threads in acrylic are inherently fragile. For any application where the screw will be removed or adjusted frequently, it’s better to use threaded brass inserts or through-holes with metal hardware.

12. What’s the best adhesive for bonding acrylic-to-acrylic?

The gold standard for acrylic bonding is solvent cement. This adhesive works by softening the acrylic surfaces so they fuse together as the solvent evaporates.

• Weld-On 4 and similar water-thin cements work with capillary action—ideal for clean, bubble-free joints.
• Thicker-bodied cements (like Weld-On 16) are used for gap filling.

For best results:

• Ensure surfaces are clean and square.
• Use clamps or fixtures to hold parts in place.
• Apply solvent sparingly to avoid bubbles.

Done correctly, the resulting joint can be nearly as strong as the acrylic itself, with excellent optical clarity.

13. Which glues work for acrylic-to-metal or acrylic-to-ABS?

Bonding acrylic to dissimilar materials requires different adhesives:

• Acrylic to Metal: Epoxies or structural adhesives work best. Avoid cyanoacrylates (superglues), as they can cause crazing.
• Acrylic to ABS/Plastics: Specialty plastic adhesives or two-part epoxies provide good results. Some urethane adhesives also work.

Always check the adhesive’s datasheet for compatibility and test on scrap material first. When possible, mechanical fasteners are more reliable for acrylic-to-metal joints.

14. Can acrylic be heat-bent?

Yes, acrylic can be bent using controlled heat. The key is temperature:

• Heat acrylic to around 290–320°F (145–160°C) to make it pliable.
• Use a strip heater for line bends or an oven for uniform heating.
• Once pliable, bend slowly and evenly, then hold in place until cool.

Acrylic will retain its new shape once cooled, but residual stress can remain. If precision and durability are critical, parts may need annealing to relieve stress after bending.

15. Is acrylic food-safe?

Most cast acrylic is considered food-safe once fully polymerized, but only for incidental contact. It is not FDA-approved for prolonged food contact like cutting boards or beverage containers. Acrylic is often used for sneeze guards, food display cases, and protective covers in food environments. For direct, long-term food contact, you’ll want to verify the acrylic’s certification or select an FDA-approved grade.

16. Is acrylic flame-retardant?

No, acrylic is not naturally flame-retardant. In fact, it is flammable and will burn if exposed to an open flame or high heat. When burning, it releases carbon dioxide, water, and carbon monoxide. If you need flame-retardant plastic, materials like polycarbonate or specialty FR acrylic sheets are better suited. Acrylic should not be used near heat sources or in environments where fire safety is critical.

17. Will acrylic crack in the cold or warp near heat?

Yes, temperature extremes can affect acrylic:

• In very cold conditions, acrylic becomes more brittle and prone to cracking under impact.
• Near heat sources, acrylic softens and may warp, bow, or creep.

The safe continuous-use temperature for most acrylic grades is 160–190°F (70–90°C). For outdoor installations in freezing climates, design with added thickness or consider polycarbonate if impact resistance in cold weather is critical.

18. How does outdoor weathering affect acrylic?

Acrylic is one of the most weather-resistant plastics available. It resists UV light, humidity, and thermal cycling better than many alternatives. Over time, however, outdoor exposure can still lead to:

• Surface micro-cracks (crazing) under stress.
• Loss of gloss from wind and abrasion.
• Minor color shifts in certain grades (though yellowing is minimal).

With proper design and occasional cleaning, acrylic can last 10–15 years outdoors with excellent optical clarity.

Key Takeaways

Acrylic is a premium plastic for laser cutting because it combines optical clarity, crisp laser-cut edges, and versatility. It’s not indestructible—it’s brittle, flammable, and sensitive to stress—but with proper design and assembly techniques, it can produce long-lasting, professional-quality parts. By understanding kerf allowances, adhesive compatibility, thermal limits, and outdoor durability, you can avoid costly mistakes and get the most out of your acrylic designs. At SendCutSend, we provide cast acrylic in multiple colors and thicknesses, laser cut to precision tolerances, with turnaround times designed for professionals, hobbyists, and businesses alike.