Part marking, serial numbers, ID plates, personalization
FM · UV · CO₂ Galvo
Which wavelength suits your material
Markers look nearly identical on paper — galvo head, small field, very fast — so buyers reasonably assume they are interchangeable. They are not, and the thing that separates them is wavelength, because wavelength decides which materials absorb the beam at all. Fiber (FM) is the metal marker. UV is the cold, gentle one for glass, ceramic, and sensitive plastics. CO₂ galvo is the fast one for organics and non-metals. Tell us the material and the decision mostly makes itself.
Match the wavelength to the material
This is the whole decision in one table. Start from what you are marking, not from the machine.
| Marker | Wavelength | Marks well | Not the tool for |
|---|---|---|---|
| FM — fiber | ~1.06 µm | Bare and coated metals — steel, stainless, aluminum, anodized aluminum, brass, some plastics | Glass; heat-sensitive plastics; most organics |
| UV | ~355 nm | Glass, ceramic, sensitive and light-coloured plastics, delicate work where heat is the enemy | Deep metal engraving — it is a surface tool |
| CO₂ galvo | 10.6 µm | Organics and non-metals — paper, card, wood, leather, cork, fabric, many films | Bare metal — metal reflects this wavelength rather than absorbing it |
The single most common mismatch
Buying a fiber marker for glass, or a CO₂ galvo for metal. Both are wavelength mismatches, not settings problems — no amount of tuning fixes a beam the material will not absorb. If you mark both metal and glass, that is a genuine two-machine conversation, and worth having before you buy either one.
Where UV earns its premium
UV costs more per watt than fiber, and on metal it is the wrong choice. Its advantage is that it works cold — the short wavelength removes material by photoablation rather than by heating it, so the heat-affected zone is minimal to none.
That matters exactly when heat is the problem: glass and ceramic that would micro-crack, thin films and coatings you need to remove without touching what is underneath, light or sensitive plastics that would scorch or melt, and medical or electronic parts where a heat signature is unacceptable. If none of those describe your work, UV is probably not worth the premium and a fiber marker will serve you better.
One practical warning about UV
Focus is the variable that decides UV results — the depth of field is genuinely shallow, so small focus errors that a fiber marker shrugs off will visibly change a UV mark. It is not difficult, but it is less forgiving. Worth knowing before you compare sample marks from two machines and conclude one is better.
What fiber marking can actually do on metal
Boss’s FM machines ship with a 20 W, 30 W, or 50 W fiber source, and Boss’s own manual gives a usefully wide working envelope: speed 1–5000 mm/s, power 10–100%, and frequency 20–80 kHz.† The reason that range is so wide is that “marking” is really several different jobs:
| Job | What it is | Where it fits |
|---|---|---|
| Annealing | A dark mark made by heating the surface, leaving it essentially flush | Stainless where the surface must stay smooth and corrosion-resistant |
| Etching / ablation | Removing a thin surface layer for contrast | General part marking, serials, barcodes, logos |
| Deep engraving | Many passes to build real depth | Marks that must survive wear, heat, or cleaning |
Wattage matters most for the third one. Deep engraving is a multi-pass job, so a 50 W source is not just “nicer” than a 20 W — it is the difference between a reasonable cycle time and one you will resent. If permanence is a requirement rather than a preference, say so below.
Colour marking, honestly
Colour marking on stainless is real and it is a genuine MOPA-source capability — but it is not a recipe you can look up and apply. Published parameter sets for the “same” colours disagree by an order of magnitude, because colour depends on that specific source’s pulse width, fill, and focal offset. Treat it as something to prove on your parts before you promise it to a customer. If colour is central to your product, tell us and we will make sure it is tested rather than assumed.
Two things worth raising early
Reflective metals. Brass and copper reflect strongly, and back-reflection into the source is a machine-protection concern rather than a settings nuisance. It is workable — typically higher frequency and more passes — but the machine should be specified for it.
Field size versus part size. A galvo marker works within a fixed field set by its lens. A part larger than the field means either a larger field with coarser detail, or moving the part and marking in sections. Tell us your largest part and the smallest text or code you need to be readable — those two numbers together decide the lens, and getting it wrong is an expensive thing to discover later.
Before you fill this in
FM · UV · CO₂ GalvoTwo answers narrow this to one machine: what material, and how permanent the mark has to be. If you can also give us your largest part size, a specialist can usually name the lens too.
Because you are on the Marking & Engraving page, we already filled these in:
- ProcessMarking / etching
Wrong guess? Clear it with × — none of this is locked in.
Frequently asked
Choosing a markerQWhat is the difference between marking and engraving?
Depth, mostly. Marking changes the surface — colour or contrast — with little or no material removed. Engraving removes material to create real depth. Annealing sits at the shallow end and deep engraving at the other, and the same machine can often do both; it is a settings and pass-count difference. More on marking vs engraving →
QWhich marker do I need for glass?
UV, for anything fine or precise. A CO₂ laser can frost and mark glass on the surface, but for detail on glass or ceramic, UV’s cold process is the right tool because it does not put heat into a material that cracks.
QWill a fiber marker mark plastic?
Some plastics, yes. But for light-coloured or heat-sensitive plastics, UV usually gives better contrast with less damage. If plastics are the main job rather than an occasional one, mention the specific polymer — it genuinely changes the answer.
QDo I need a marker or a cutter?
A marker changes a surface; it does not cut parts out. If you need to produce the part as well as mark it, that is a cutter — fiber for metal, CO₂ for non-metals — and some shops run one of each.
Sources & what still needs confirming
† FM source options and the speed / power / frequency envelope are from Boss’s own FM Series user manual. Specific parameter recipes per material are industry-typical starting points, not Boss-validated settings — published tables are mostly 20–30 W desktop class and do not scale unchanged to a 50 W machine. Build a test grid on your own material before committing to a production setting.
Not what you were after?
Need to cut, not mark?
Go back up a level and re-pick, and nothing here will be preselected for you.