How to Use the xTool M1 Ultra for Acrylic: A Practical 8-Step Workflow for Accurate Cuts & Engraves

If you’ve just unpacked an xTool M1 Ultra and have a stack of acrylic sheets waiting, you’re probably less interested in the theory of laser-material interaction and more in how to get a clean cut without melting the edges. This guide is for that exact scenario. Eight steps. No fluff. Let’s go.

Why This Workflow Exists

When I took over purchasing for our studio in 2022, I assumed all desktop lasers were pretty much the same. Place material, hit print, done. The xTool M1 Ultra proved me wrong immediately. Its 4-in-1 design (laser, knife blade, print head) means you have to think about which tool to use for which job, especially with a material as finicky as acrylic. Cast vs. extruded. Clear vs. colored. The difference between a perfect edge and a frosted, cracked mess is about 10% machine setting and 90% knowing what you’re looking at.

The 8-Step Checklist for Acrylic on the xTool M1 Ultra

Step 1: Identify Your Acrylic Type

This is the step most people skip, and it’s where I went wrong on my first job. Grab a flashlight and shine it at the edge of the sheet.

• Clear edge = Extruded Acrylic. This cuts beautifully with the laser. Clean flame-polished edges.
• White/Cloudy edge = Cast Acrylic. This engraves beautifully but is prone to cracking and chipping when cut with a laser.

A good rule of thumb—or rather, something I learned from ruining a $40 sheet of cast acrylic—is that if you need precise, crack-free parts, use extruded. If you need deep, frosted engraving, use cast. It took me about 20 practice cuts and 3 ruined pieces to understand that. A more gradual realization, sure, but a lesson that stuck.

Step 2: Calibrate the IR Laser and the Knife Blade

The M1 Ultra has multiple tool heads. For acrylic, you are likely using the IR laser (1064nm) for fine engraving or the diode blue laser (455nm) for cutting, and possibly the knife blade for creasing or scoring. You must calibrate the height of the knife blade separately from the laser.

• Laser Focus: Use the included focus gauge. For acrylic, the focus point is critical. Off by 1mm and you're melting instead of vaporizing.
• Blade Force: This is where the 'xtool m1 ultra blade cutting force' comes in. If you're using the drag knife to cut thin acrylic (1-2mm), you need to set the blade force high enough to cut through, but not so high it cracks the material. I start at a force of 8 on the XCS software for 1.5mm extruded acrylic and adjust up or down. Start low, test on a corner, increase. It’s not a race.

Step 3: Set Material Thickness in XCS

Obvious, right? But the XCS software (xTool Creative Space) needs the exact thickness to adjust the z-axis for the knife blade and the laser. Use calipers. Don't guess. “Oh, it’s about 3mm” is a recipe for a misaligned cut. Input the exact decimal, e.g., 3.17mm.

Step 4: Apply Tape (For Clear Acrylic Cutting)

If you are cutting clear acrylic, apply blue painter's tape or transfer tape to the top surface. This does two things: it prevents the laser exhaust from depositing micro-soot onto the surface (which causes a frosted edge), and it helps prevent the laser beam from reflecting back up into the lens on shiny surfaces. Yes, that reflection can damage the diode. A lesson learned the hard way from a colleague who lost a lens.

Step 5: Test Cut Geometry

Never cut your final design first.

In XCS, set the laser to cut a small square (10x10mm) from your material. Use the 'Test Cut' function if your software has it. This is your baseline. If the square doesn't fall out cleanly, increase the power by 5% or decrease speed by 10mm/s. If the edges look milky or yellow (over-burning), decrease power. Write down the final settings on a sticky note and attach it to the material. I keep a notebook in the shop,

Step 6: Fine-Tune the 'Cutting Force' for the Knife

For the knife blade on thin acrylic, you are looking for a specific cut quality. The cut line should be a clean V-groove. If the back of the acrylic has a white stress line, the blade force is too high. Reduce it by 0.5 points. If the blade skips and doesn't cut the top layer, increase it by 1 point. The perfect setting is when you can snap the piece cleanly along the scored line with minimal pressure.

"If I could redo that decision, I'd invest in better specifications upfront. But given what I knew then—nothing about the vendor's interpretation quirks—my choice was reasonable." — That applies here. Knowing your acrylic type and how the blade interacts with it is the single biggest time-saver.

Step 7: Engraving Settings for Depth and Contrast

This is more of a checklist item. For laser engraving on acrylic (using the blue diode):

• Low & Slow: 60% power, 150mm/s speed, 0.1mm per pass. This gives a frosted white finish on cast acrylic.
• High & Fast: 80% power, 250mm/s speed. This gives a bubble or 'bloom' effect, which can be cool for certain designs but looks unprofessional for most logos.

For metal engraving designs (anodized aluminum or coated stainless steel), you need a different approach. Use the IR laser at 300dpi, 100% power, and 400mm/s speed. This will mark the coating without melting the metal. I want to say it took me 5 attempts to get a consistent black mark on a stainless steel dog tag, but don't quote me on that—it might have been 6.

Step 8: Post-Processing and Cleaning

Even after a perfect cut, you're not done.

• Remove tape: Do this immediately while the piece is still warm. The adhesive releases easier.
• Clean edges: For laser-cut acrylic, you can flame-polish the edges with a butane torch (quick pass, don't linger). For knife-cut acrylic, sand the edge with 600-grit paper to remove any micro-burrs.

Two Common Mistakes to Avoid

Mistake #1: Assuming 'Acrylic' Settings Are Universal

We discussed cast vs. extruded, but there's another variable: color. Darker acrylics absorb more laser energy and require 10-15% less power to cut than clear or white acrylic. Always test on a scrap piece the same color.

Mistake #2: Forgetting About Air Assist

The M1 Ultra has an air assist function. For laser cutting acrylic, you must use it. The air flow purges the cut kerf of combustible gases, reducing the flame and keeping the edge clean. Cutting acrylic without air assist is like trying to cut butter with a hot knife—it just melts and sticks. Worse than expected, every time.

This workflow is what I use for every single acrylic project now. It took probably 50 hours of trial and error to develop, but it turns a potential 2-hour headache into a reliable 30-minute process. If you're also working with EVA foam, the process is similar—just use a lower power laser setting (15-20%) and a slower speed. And for the Hypertherm plasma cutter reference you see online? That's for steel. Different machine, different rules. Stick with this for your desktop acrylic work.