If you've ever typed "what cuts acrylic sheets" into Google at 11pm, you know the feeling. You have a product idea, a shopping cart full of acrylic, and a spec sheet that reads like it was written in another language. Most people in that situation end up asking one question: how many watts do I need?
I've been on both sides of that search. I'm not a laser engineer and I'm not going to pretend to be one. I run a small workshop in the UK making small-batch products—signs, keyrings, wedding favours, the usual side-hustle to full-time-shop pipeline. Six years ago I knew nothing about lasers. Three machines and roughly £1,100 in avoidable expenses later, I can tell you exactly where most people go wrong.
The question isn't wrong. But the spec sheet you're asking is.
The "40W" machine I bought wasn't 40 watts
In late 2019, I bought a "40W laser cutter" from a marketplace for £450. The listing said 40W. The box said 40W. The unboxing video I made said "wow, 40 watts" in an excited voice that I now find embarrassing to remember.
It took me three weeks to accept that this machine could not cut 3mm clear acrylic. The edges melted. The surface scorched. Anything over 2mm and the cut would just... stop. I bought a replacement lens, fitted an air assist kit, and watched every YouTube tutorial that mentioned "acrylic laser settings." The best cut I ever got out of it looked like something had gnawed through the sheet.
Here's what I didn't know: "40W" referred to input power. The module drew 40 watts of electricity. The actual laser output was closer to 5–7 watts. And more importantly, it was a diode laser at 455nm—blue light. And blue light passes straight through clear acrylic. It's not absorbed. It's the worst possible wavelength for the job.
Everyone with actual laser experience knows this. Nobody told me before I clicked "Buy now."
Wattage isn't one number. Sometimes it's a marketing number.
This is why the "glowforge aura wattage" question comes up over and over. People see 20W on the Aura's spec sheet, then see "40W" on a budget machine for half the price, and assume the budget machine is twice as capable. I would have made the same assumption in 2019.
But a 40W diode laser and a 40W CO2 laser are different species. They share a word in the product description and almost nothing else.
CO2 lasers emit at 10.6 micrometres—far-infrared. Acrylic absorbs that wavelength extremely well, which is why a CO2 laser can cut cleanly through clear acrylic with far less power than a diode needs. The Aura uses a CO2 source—Glowforge lists the Aura's laser at 20W on its official specifications (glowforge.com, accessed January 2025; verify current specs before purchase). So when people search for "glowforge aura wattage," the useful answer isn't "20W." The useful distinction is that CO2 is the wavelength acrylic actually responds to.
Think of it this way: "higher wattage is better" is true in the same way "a louder car is faster" is true. Sometimes, within the same category, it works. But it completely misses what's actually going on.
I only believed this after seeing it. My old diode machine on one side, the Aura on the other, same sheet of 3mm acrylic, same file. Watching the Aura make one clean pass in a fraction of the time was one of those moments where the last two years of frustration suddenly made sense. It wasn't a wattage gap. It was a technology gap.
When I look back at my search for a "glowforge aura laser engraver" before buying, I noticed most reviews focused on the software and the ease of use. I figured those were nice-to-haves. Turns out they matter more than the laser itself. The Aura auto-focuses, which doesn't sound impressive until you've spent months manually setting focus on a diode machine and getting it wrong a third of the time. The software has calibrated material settings, so you don't burn test sheets trying to find the right speed and power. These aren't gimmicks. They're the difference between a machine you use and a machine you fight.
The die cutting machine detour
Somewhere between the diode laser failure and finally buying a real CO2 machine, I made the same mistake I see in UK maker groups every single week. Someone searches for a "die cutting machine uk" because they want to make products out of acrylic. They buy a blade-based machine designed for paper. Then they come back asking why it can't do the thing they actually need.
I did exactly that in 2020. Paid £280 for a die cutting machine. To be fair, it's still on the bench today—it cuts cardstock and vinyl beautifully, and the sticker side of our business relies on it. I'm not here to trash die cutting machines. They're genuinely good tools.
But they cannot cut a 3mm rigid acrylic sheet. A die cutting machine uses blade pressure. It physically presses through material. It is a separate technology from a laser, and the only thing the two have in common is that both happen to cut paper. If your end goal is acrylic keyrings, edge-lit signs, or anything rigid, a die cutting machine is not a stepping stone. It's a detour.
What three wrong tools actually cost me
Let me put the numbers down while I'm feeling honest. I want to say these are accurate—it's been a few years, so don't quote me on the pence.
- "40W" diode laser: £450
- Replacement lens and air assist kit: £90
- Die cutting machine: £280
- Acrylic ruined during "testing" (3mm and 6mm, cast and extruded): roughly £250
- Miscellaneous materials I burned while trying to make the diode work: £80
That's £1,150 in hardware and wasted material. Add the 300 hours I spent trying to make the wrong tools do the right job, and even at a modest £15 an hour, the opportunity cost is another £4,500. I don't think I've admitted that number out loud until now.
This is what I mean by total cost of ownership. The sticker price is the smallest part of a machine's real cost. Upgrades, wasted materials, troubleshooting hours, missed deadlines—they're all part of the purchase. A "cheap" machine that makes you a part-time technician isn't cheap. Good design is not a luxury. It's a cost-saving feature.
The Glowforge Aura is more expensive upfront. I want to say it launched in the UK at just over £1,000, though Glowforge has changed pricing since, so check glowforge.com for the current figure. But it produced a usable cut on the first try. I didn't buy upgrades for it. I didn't donate a stack of acrylic to the learning curve. I chose a material setting, ran a test, and made a real part on day one.
In total cost terms, it's the cheapest machine I've ever owned.
"The £400 quote turned into £640 after shipping, setup, and revision fees. The £520 all-inclusive quote was actually the cheaper one." The same principle applies to laser machines, once you add up everything you'll spend after the box arrives.
What I'd check before you buy anything
If you're where I was in 2019, here's the short version. I'm not going to make it a 47-point checklist, because you'll skip the list and buy something anyway. Four things:
- Match the technology to the material. Acrylic, wood, leather, stone: CO2 laser. Paper, vinyl, cardstock: die cutting machine. They're not interchangeable.
- Check whether the wattage is optical output or input. If a "40W" machine costs half as much as a "20W" machine, the cheaper number is probably electricity. The expensive one is probably laser light.
- Buy the system, not the hardware. Software, focus, enclosure, and material presets decide whether you succeed in week one or month six. The Aura's ecosystem is precisely why it's worth the extra money to so many small businesses.
- Test on scrap before you test on anything valuable. That's a £250 lesson. You can have it for free.
One caveat: I'm speaking from the small-batch, workshop-scale side of the industry. If you're running a full production line cutting sheets all day, you need a bigger machine and a very different budget. My advice is for the people with a product idea and an 11pm search bar.
So, what actually cuts acrylic sheets?
A CO2 laser. That's the whole answer. Not "a bigger laser." Not "a die cutting machine." A CO2 laser. And the Glowforge Aura's 20W happens to be a well-implemented CO2 system that handles the materials most small businesses actually use.
Once that question is settled, you'll hit the second layer of the acrylic problem: cast vs extruded. Extruded acrylic cuts faster and a CO2 laser flames its edge crystal clear. Cast acrylic engraves white and leaves a frosted finish. I'm not a materials scientist, so I can't walk you through the polymer chemistry. What I can tell you from a production perspective is that this distinction will affect your product quality more than the wattage number ever will. But that's a separate article.
I'm glad I tested the Aura on scrap before running a real order. I almost went straight to a £120 sheet of 6mm black acrylic on the first cut. One wrong setting and that would have been another line on the waste list.
The question you started with—"what cuts acrylic sheets"—is the right one. The trap is believing the answer is a single number. It's a wavelength, a technology, a system, and a realistic view of the total cost. Get those four things straight, and you skip the £1,150 mistake I spent a year making.
The Glowforge Aura is 20W. The reason it works isn't the 20W. It's everything around the 20W.
