Laser engraving machine cutting an oak veneered MDF sign in a workshop

What Is Laser Engraving? How It Actually Works (From Someone Who Runs Two Commercially)

Laser engraving uses a focused laser beam to vaporise, char or discolour the surface of a material, leaving a permanent mark with no ink and nothing touching the surface. A CO2 laser with a standard 2-inch lens focuses to a spot roughly 0.1โ€“0.2 mm across. Laser cutting uses the same beam to go right through.

Every week someone visiting the workshop, or messaging us on Instagram, asks some version of the same question: what actually is laser engraving, and how is it different from laser cutting? Fair question. We've run OMTech CO2 lasers in daily production here in Buckley since January 2023, and two of them since June 2024, so here's the honest, no-fluff answer โ€” not the version written by someone who's never stood next to a running machine.

What is laser engraving?

Laser engraving is a process that uses a focused beam of light to remove or alter the surface of a material, leaving a permanent mark. No ink, no physical tool touching the surface, no template. The laser does the work by heating the material until it vaporises, chars or discolours in a precisely controlled pattern โ€” whatever pattern you've designed on a computer and sent to the machine.

That's the textbook version. In practice, what it means day to day in our workshop is: we can take a plain piece of FSC-certified oak veneered MDF, birch plywood or acrylic and turn it into a name badge, a house sign or a trophy with detail fine enough to read a 6pt font, repeatably, at commercial volume, without a single physical stencil or mould.

How does laser engraving actually work?

The machine fires a laser beam through a lens that focuses it down to a tiny spot: with a standard 2-inch lens, a CO2 laser focuses to roughly 0.1โ€“0.2 mm. On a gantry CO2 like our OMTechs, the tube stays still and three mirrors carry the beam from the tube to a head that moves on X/Y rails; the head holds the final mirror and the focus lens. (Galvo machines, mostly fibre markers, steer the beam with fast-moving mirrors instead, and diode machines move the laser module itself.)

The head follows the design file in one of two ways. For a raster job it scans back and forth, line by line, to fill in areas, text and images. For a vector job it follows outlines, for cuts and score lines. Where the beam passes, the energy is absorbed by the material and converted to heat. Depending on the material and the power and speed settings, that heat:

  • Vaporises the surface, leaving a shallow, precise recess (most engraving on wood, acrylic and leather).
  • Chars or discolours the surface without removing much material (common on lighter woods, giving that classic dark laser-engraved look).
  • Removes a coating, or fuses one on, which is how metals mark: anodised aluminium marks when the beam removes or bleaches the dyed anodised layer, and bare metal marks only when a marking compound such as CerMark is fused onto the surface.

The two variables that matter most are power (how much energy is in the beam) and speed (how long the beam dwells on any one spot); focus and, for engraving, line interval matter too. Get the combination wrong and you either don't mark the material at all, or you burn straight through it. Getting that balance right, material by material, is most of what separates a machine that can technically engrave from a workshop that can reliably deliver a finished product to a paying customer. LightBurn's Material Test grid is a quick way to find it on your own machine, and we also run a 2-hour training session if you want help with it.

Laser engraving vs laser cutting vs laser etching โ€” what's the actual difference?

These terms get used almost interchangeably online, and definitions vary, which is genuinely confusing if you're new to this. Here's how we'd draw the lines:

  • Engraving removes material to a controlled depth, leaving a recess you can feel with your fingernail. Used for detail, texture and depth.
  • Etching is a shallow, surface-level mark โ€” often just discolouration with barely any material removed. Some sources treat it as a separate process; many people use "engraving" and "etching" interchangeably, which is why you'll see both used for the same result. A third term, marking, usually means changing the surface without removing any material, as with a marking compound on metal.
  • Cutting takes the beam all the way through the material, separating it into pieces. Same machine, same laser, completely different job โ€” higher power and slower speed than engraving, with the focus set for cutting rather than surface detail.

On a day-to-day basis we'll often do all three in a single job: cut a wooden sign down to a custom shape, engrave the text and logo onto its face, and etch a lighter, decorative pattern around the edge โ€” all on the same OMTech machine, just with different settings loaded for each layer.

CO2 vs fibre vs diode โ€” which laser does what

Not all laser engravers are the same technology, and it matters when you start shopping for a machine. The main difference is the wavelength, which decides which materials absorb the beam.

  • CO2 lasers (about 10.6 ยตm, far infrared โ€” what we run) are the workhorse for organic and semi-organic materials: wood, acrylic, leather, card, slate and glass (engraved, not cut), plus anodised or coated metals. They're the most versatile option for a general engraving and cutting business, which is exactly why we chose OMTech's CO2 range when we set up commercially.
  • Fibre lasers (about 1.06 ยตm) are built for metal โ€” stainless steel, aluminium, brass โ€” marking permanently without coatings or sprays, and faster than a CO2 for metal work. But they can't cut wood or acrylic in the way a CO2 machine can.
  • Diode lasers (blue, about 450 nm) are the smaller machines many people compare with a CO2 when they start out. They engrave wood and other organic materials, but they can't process clear acrylic or clear glass, because the beam passes straight through.

If you're choosing a first machine for a general engraving business in the UK, CO2 is almost always the right starting point โ€” it's the widest range of materials for the money. We've written a separate, warts-and-all breakdown of how OMTech's CO2 machines actually compare to HPC and Trotec if you're at that stage: OMTech vs HPC vs Trotec โ€” what are you actually paying for.

What can you actually engrave?

Since our first OMTech arrived, the materials through our machines have included wood, acrylic, glass, leather, slate, anodised aluminium, coated stainless steel and card. The realistic list of what a CO2 laser handles well: wood and plywood, acrylic, vegetable-tanned leather, glass (frosted, never cut), slate and stone, card and paper, and anodised or coated metals. Bare, uncoated metal is the main material a CO2 machine won't mark on its own โ€” that needs a marking compound or a fibre laser.

Some materials must never go in at all: PVC and vinyl; neoprene; PTFE (Teflon); ABS; polycarbonate; and anything you can't identify. Vegetable-tanned leather is fine; avoid chrome-tanned leather and most faux leather (often PVC). For a tour of what a CO2 laser makes, material by material, read what can you make with a CO2 laser engraver.

Why this matters if you're buying a machine, not just a product

That's the theory. We'd rather point you at what actually happens once the machine is running in a real workshop, because that's the part that decides whether this is a hobby or a business:

Want to see it running before you commit?

Reading about laser engraving only gets you so far โ€” the fastest way to understand it is to watch a commercial machine actually cutting and engraving in front of you. We're an official OMTech showroom here in Buckley, North Wales, a short drive from Chester, Mold and Deeside. Visits are free, informal and by appointment; how to book is on our OMTech showroom page.

Frequently asked questions

What is laser engraving?
Laser engraving uses a focused laser beam to vaporise, char or discolour the surface of a material, leaving a permanent mark. No ink is used and nothing touches the surface.

What is the difference between laser engraving and laser etching?
Engraving removes material to a depth you can feel. Etching usually means a shallower surface mark, though definitions vary and many people use the two words interchangeably.

What is the difference between laser engraving and laser cutting?
Engraving marks the surface, while cutting takes the beam all the way through the material, using higher power and slower speed. A CO2 laser can do both in the same job.

Which type of laser is best for engraving?
For wood, acrylic, leather and glass, a CO2 laser (about 10.6 ยตm) covers the widest range of materials. Fibre lasers (about 1.06 ยตm) suit bare metal, and blue diode lasers (about 450 nm) can't process clear acrylic or clear glass.

Can a CO2 laser engrave metal?
It marks anodised aluminium directly. Bare metal reflects the CO2 beam, so it needs a marking compound such as CerMark, or a fibre laser.

Sources

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