The single most expensive misunderstanding in this trade is assuming one laser does everything. Here is which does what, and why.
An engraving quote comes back at triple what you expected, or a supplier says flatly that they cannot do the job. Nine times out of ten the explanation is not commercial. It is that your material and their laser do not get along, and nobody has explained why.
There are three types in common use here. Each one is defined by its wavelength, and wavelength decides what the beam is absorbed by. That is the entire story.
The numbers are far apart. Keyence, a maker of industrial laser markers, gives the wavelengths as 1,090 nm for fiber, 355 nm for UV and 10,600 nm for CO2. The CO2 beam is nearly ten times longer than fiber's, and Keyence notes that it is nearly impossible to mark metal with it, because metal does not absorb that light, while fiber light passes straight through transparent materials.
Fiber: the metal laser
Fiber lasers are absorbed strongly by metal. They mark steel, stainless, aluminium, brass, titanium and coated metals cleanly and fast, and they handle many hard plastics.
This is the type behind almost all asset work: handheld fiber markers (KSh 290,000 for a 30W unit, in stock) are what put numbers on chairs, codes on rims, names on cutlery and identifiers on tools. They are portable, which is what makes marking on a client's premises possible at all.
What fiber will not do: clear glass, most untreated wood, and paper, because the beam passes through them or scorches them instead of marking.
UV: the cold laser
UV lasers work at a much shorter wavelength, and the effect is different in kind. Instead of heating the surface, the beam breaks the bonds at it. The practical result is a mark with almost no heat spread, which is why UV is the answer for materials that would burn, warp or discolour.
Glass, delicate plastics, coated and painted surfaces, and anything where a scorch ring around the mark is unacceptable. A handheld UV marker is KSh 420,000 for 5W, against KSh 290,000 for a 30W fiber handheld, so UV costs more for less power, because it does work fiber cannot do at all.
CO2: the organics laser
CO2 is the long-wavelength type, absorbed by organic materials and by acrylic. Wood, leather, card, fabric, rubber, acrylic sheet. It is the type in most laser cutting machines (ours, a 180W machine with a 3 x 4 ft bed, is KSh 700,000), because those same materials are the ones people want cut, not merely marked.
What CO2 will not do is mark bare metal. It will mark a coating on metal, which is a distinction that confuses a lot of buyers: a CO2 machine can put your logo on a painted steel plate and cannot put it on the steel underneath.
Decide the work first: people buy on price and discover afterwards that the one material their customers bring is the one their laser cannot touch. Write down the five materials you expect to work with, then choose.
The comparison, in one place
- Metal, bare or coated: fiber. UV also works and costs more.
- Glass and crystal: UV. Fiber will not; CO2 frosts it unevenly.
- Wood, leather, card, fabric: CO2.
- Acrylic, cut or engraved: CO2.
- Hard plastics and cable ties: fiber, usually. Test first; plastics vary more than any other category.
- Heat-sensitive or painted surfaces: UV.
- Anything you need to cut through: CO2, and a machine sized for the thickness.
What this means if you are buying
For asset marking, tags, tools and vehicles, fiber is the answer, and the decision is about portability and support, not type. For signage, awards and decorative cutting, CO2. For glass, gifts and delicate items, UV, and expect to pay for it.
Most working shops end up with two machines, because the material lists barely overlap, and that is worth knowing at the start, not after the first purchase.
What this means if you are buying the service, not the machine
The same information saves you a wasted trip. If a supplier says they cannot engrave your glass award, they are not being difficult. They probably have a fiber machine, and fiber does not mark clear glass. Ask what type they run before you carry anything across town.
It also explains price differences that otherwise look arbitrary. A glass job quoted at three times a metal job of the same size is usually not a markup; it is a different machine, bought at a higher cost, doing work the cheaper machine physically cannot. Knowing that turns a suspicious quote into a comprehensible one.
Whichever type you land on, the questions to ask a seller apply. For asset marking, the list of jobs people ask for is the better place to start.
Sources: Keyence, fiber vs CO2 vs UV laser markers (read 14 Oct 2026).
Common questions
Can one machine handle metal and wood?
Not properly. Fiber marks metal and scorches wood; CO2 cuts wood and cannot touch bare metal. Machines advertised as handling both are usually CO2 units marking a coating on the metal, not the metal itself, which looks identical until the coating wears. If both materials are core to your work, plan for two machines.
Why is UV more expensive for the same wattage?
Because the wavelength is produced by converting a longer one, and that conversion loses efficiency and adds components. You are not paying for more power. You are paying for a beam that marks without heat, which is the only way to work on glass, delicate plastics and finished surfaces without damage.
Does the wattage matter more than the type?
No. Type decides whether the material can be marked at all; wattage decides how fast. A 20-watt fiber and a 50-watt fiber both mark stainless steel, one just does it quicker. A 100-watt CO2 will still never mark bare stainless. Choose type first, then power for your volume.
Can I bring a sample to test before deciding?
Yes, and it is the sensible thing to do. Bring the material you intend to work with, not something similar: two plastics that look the same can behave completely differently. A test piece takes minutes and settles a question that a specification sheet cannot.
