The ones laser makers list as prohibited, which typically include PVC and other chlorine-containing plastics, polycarbonate for cutting, and unknown coated or treated materials. Checking what a material is before engraving it is the rule, because some release harmful gases or catch fire easily.
A laser vaporises what it touches, so the material decides what enters the air.
Where the prohibited materials lists come from
Laser makers publish lists of materials not to process, and material suppliers publish what their products release when heated. Both lists come before any engraving.
Materials commonly on laser makers’ prohibited lists
PVC, vinyl and other chlorinated plastics, which release corrosive and harmful gases. Polycarbonate for cutting, which burns and discolours. Fibreglass and some coated materials. Unknown plastics and treated materials whose composition is not stated.
Materials that need extra care under a laser
MDF and plywood produce heavy smoke from binders and glues. Leather can be chrome-tanned or treated. Foams vary widely, and some melt and ignite readily.
Workspace precautions for laser materials
Extraction or filtration, eye protection marked for the laser’s wavelength, supervision while running and a fire extinguisher nearby, as laser makers commonly list.
What this site does not claim
No material or setup is described here as safe to process. The laser maker’s material list and the supplier’s information decide.
If this page and the manufacturer’s manual disagree, follow the manual. Every laser power, speed, build volume, resolution, temperature and safety rating on this page is taken from the maker’s own documentation, with its unit as published and its source named — none of it is measured here. A figure is written the way the maker states it and is not converted into another convention, because the converted value would be a different number. And the limit this page does not cross: no enclosure, filter, extractor, pair of glasses or setting is described here as making a machine safe. The page reports what the maker supplies and what the markings state — a laser class, a filter type, an optical density at a stated wavelength — and the manufacturer’s instructions decide the rest, because the room, the material and the use are beyond what any listing can know.
Questions makers ask before buying
How can I tell whether a plastic is PVC?
Supplier information and labels are the reliable route. If a sheet’s material is unknown, laser makers advise not processing it.
Is MDF safe to engrave?
MDF is commonly laser-cut, and its binders produce smoke that needs extraction. The laser maker’s material list and the MDF supplier’s information describe any precautions.
Last reviewed 15 September 2026