Fibre lasers mark metals, while CO₂ lasers mark plastics, laminates, and other non-metal surfaces. The two systems use different wavelengths, so each one suits a different set of laser engraving materials. Get the wrong laser for the job, and you will end up with a faint mark or no mark at all.
Businesses looking at stainless steel engraving machines often assume one laser type handles everything. It does not, and knowing the difference saves you time, money, and a lot of trial and error.
Let’s take you through what each laser marks well, where compounds like Cermark come in, and how to choose the right system for your materials.
How Fibre and CO₂ Laser Systems Interact with Materials
A fibre laser runs at a wavelength of around 1064 nm. Metals absorb this wavelength efficiently, which lets the beam heat and vaporise a thin surface layer to leave a mark. This is why fibre laser materials are almost always metals or metal-coated surfaces.
A CO₂ laser runs at a much longer wavelength, around 10,640 nm. Plastics, laminates, wood, and glass absorb this wavelength well, but most bare metals reflect it straight back. That reflection is the main reason CO₂ laser materials rarely include untreated metal.
Which Materials Are Commonly Marked with Fibre Lasers?
Fibre lasers are the standard choice for direct metal marking. Common fibre laser materials include:
- Stainless steel, in both 304 and 316 grades
- Mild steel and coated steel components
- Anodised aluminium plates and valve tags
- Titanium and other specialty alloys
- Brass and other copper-based alloys
Businesses that rely on stainless steel engraving machines use them for compliance plates, cable markers, and asset tags that need to survive years of outdoor or industrial use.
The mark sits within the metal surface itself, rather than sitting on top of it as ink or paint would.
Which Materials Are Commonly Engraved or Cut with CO₂ Lasers?
CO₂ lasers handle a different range of laser engraving materials, mostly non-metals. Typical CO₂ laser materials include:
- Traffolyte and other laminated plastic sheets
- Rowmark LaserMax and LaserMark engraving plastics
- Acrylic, timber, and MDF
- Cardboard, leather, and some fabrics
- Glass and certain ceramics
Traffolyte engraving machines are a common sight in electrical and signage workshops, since Traffolyte cuts cleanly and reveals a contrasting colour layer underneath. This makes it ideal for switchboard labels, name plates, and safety signage where the text needs to stand out clearly.
When Does CO₂ Marking on Stainless Steel Requires Cermark or Another Marking Compound?
A CO₂ laser cannot mark bare stainless steel on its own, since the metal reflects that wavelength rather than absorbing it.
Applying a compound such as Cermark tape or paste changes this. The compound absorbs the CO₂ beam and bonds to the metal surface when heated, leaving a dark, durable mark.
This method works well for lower-volume jobs or workshops that already run a CO₂ system for other CO₂ laser materials.
It is a workaround rather than a direct marking method, though, and it adds an extra material cost and an extra step to the process. For high-volume metal marking, a dedicated fibre laser is usually the more practical option.
Why Plastics, Coatings and Surface Finishes Need Sample Testing?
Not every plastic or coated surface reacts to a laser in the same way. Colour, thickness, coating type, and even the batch of material can all change how a mark looks.
A setting that works perfectly on one sheet of Traffolyte might scorch or barely mark another. This is why sample testing matters before running a full production batch. It is worth testing on:
- A new colour or brand of laminate or plastic
- A coated or painted metal surface
- A different grade or finish of stainless steel
- Any material you have not marked with that laser before
Direct Marking, Engraving and Coated Marking: What Is the Difference?
Direct marking uses the laser alone to change the surface of the material, without any added compound. This covers most fibre laser materials, since fibre lasers mark bare metal directly, and it also covers plastics like Traffolyte and acrylic under a CO₂ laser. The result is a permanent change to the material itself.
Engraving goes a step further and removes material to cut through a top layer, revealing a different colour or texture underneath. This is how two-tone Traffolyte plates get their contrast.
Coated marking, on the other hand, relies on an applied compound such as Cermark to create the mark, rather than changing the base material directly.
How To Choose the Right Laser for the Material and Required Result?
Picking between a fibre and a CO₂ system comes down to what you need to mark, and how often. A workshop running mostly fibre laser materials has very different needs to one running mostly CO₂ laser materials. Before choosing, think through:
- Whether your parts are mostly metal, mostly plastic, or a mix of both
- The finish and durability your industry or compliance standards require
- Your production volume and how often settings will need to change
- Whether you need training, installation support, and ongoing servicing
Engraving Supplies has supplied engraving machines across Australia for over 50 years, and our team can help you match the right laser engraving materials to your actual production needs.
We supply stainless steel engraving machines, Traffolyte engraving machines, and the consumables that go with each, along with installation, training, and technical support.
Closing Thoughts
Fibre and CO₂ lasers are not interchangeable, since each one suits a different group of laser engraving materials.
Fibre lasers handle metal directly, CO₂ lasers handle plastics and laminates directly, and compounds like Cermark bridge the gap when you need a CO₂ system to mark stainless steel.
Get in touch with Engraving Supplies for advice on the right machine for your materials, or ask about our free engraving and labelling consultation before you commit.
1. Which materials can fibre lasers mark directly?
Fibre lasers mark bare metals directly, including stainless steel, mild steel, anodised aluminium, titanium, and brass. The beam heats and vaporises a thin surface layer to leave a permanent mark on the metal itself.
2. Which materials are suited to CO₂ laser systems?
CO₂ lasers suit non-metal materials such as Traffolyte, acrylic, timber, leather, cardboard, and glass. Most bare metals reflect the CO₂ wavelength, so they are not marked well by this laser type alone.
3. Can a CO₂ laser mark stainless steel using a marking compound?
Yes. Applying Cermark tape or paste to the surface gives the CO₂ beam something to bond with, creating a dark, durable mark. It works well for smaller runs, but a fibre laser is usually more practical for regular metal marking.
4. Why should plastics and coated materials be sample tested?
Colour, thickness, and coating type all affect how a material reacts to a laser, even within the same product range. A quick test piece confirms the settings before you commit to a full production batch.
5. How do you choose the right laser for a material?
Start with whether your parts are mostly metal or mostly plastic, then factor in your required finish, production volume, and compliance needs. A supplier who understands both fibre and CO₂ systems can help you match the right machine and settings to your materials.
