A list of things you definitely should not put in your laser.
We recently got the Bambu Lab H2D "full laser" combo in for testing, which has, you guessed it, a LASER! Because I'm testing it for Tom's Hardware, I got both the 40w and 10w lasers.
This isn't my first time working with a laser -- I've tested several others, including some fine lasers by xTool and Glowforge. One of the problem you'll run into with buying a hobby laser is knowing what is and is not safe to laser. You may not think about it, but a lot of common materials are made of (or bonded with) chemicals. And chemicals, for the most part, should not be set on fire. Which is exactly what your laser is doing.
Disclosure: I am not a chemist or a medical researcher. I am a journalist and an amateur laser enthusiast. I can not give you medical or legal advice...but I can share some common sense.
What is Safe to Laser?
The easy answer here is to stick with natural, untreated items. Good choices include:
- Raw wood (no paint, stains, or glues)
- Paper and cardboard (avoid anything coated or waxed)
- Leather (only if it’s vegetable-tanned, not chemically processed)
- Certain plastics (like acrylic, but only cast acrylic, not extruded)
- Some plywood (best to use laser safe plywood for crafting)
If you’re unsure, check the manufacturer’s guidelines or do a quick burn test in a well-ventilated area—if it smells awful or releases dark smoke, it’s probably unsafe.
Where Can I Get Laser Safe Materials to Craft?
Your best bet is to shop with the laser companies themselves, who all carry full lines of materials for their lasers. You can mix and match: you don't need a Glowforge to buy Glowforge material. Just keep an eye on the size, as Glowforge and xTool offer large sheets for their bigger machines.
Glowforge sells "Proofgrade" materials that are pre-sanded and finished with laser safe coatings. They also come with a protective sticker that you can keep on the material to prevent smoke staining & char, which is especially handy if you don't have air assist or a fast laser.
Can You Laser PLA?
PLA (Polylactic Acid) is one of the most common 3D printing filaments, but it’s not the best choice for laser cutting or engraving.
✅ Safe to burn – PLA doesn’t release toxic fumes like ABS or PVC.
⚠️ Melts rather than burns – Instead of vaporizing cleanly, PLA softens and deforms, leading to messy cuts and residue buildup on your laser’s lens.
⚠️ Watch out for additives – PLA filaments with glitter, wood fibers, or carbon fiber may contain non-laser-safe materials.
Recommended Laser Settings for PLA
PLA is difficult to cut cleanly, but you can engrave it with some success. Here are some starting points for testing:
For a 10W Diode Laser
- Engraving: 30-50% power, 2000-3000 mm/min, 1 pass
- Cutting (not recommended, but possible on thin sheets): 100% power, 200-400 mm/min, multiple passes
For a 40W Diode Laser
- Engraving: 20-40% power, 2500-3500 mm/min, 1 pass
- Cutting: 100% power, 500-800 mm/min, multiple passes (best with thin PLA sheets, not 3D prints)
💡 Pro Tip: Use air assist to prevent burning edges and sticky residue buildup. If your PLA starts melting into a gooey mess, lower the power and increase speed.
What Should You NEVER Put in a Laser?
Now for the bad stuff. These materials can release toxic fumes, start fires, or damage your laser. Some of them are common in a 3D printing workspace, so be extra careful.
3D Printing Filaments to Avoid
Not all filaments are laser-friendly! Some release hazardous gases when burned:
- ABS (Acrylonitrile Butadiene Styrene) – Produces cyanide and styrene gas (toxic and carcinogenic).
- PVC (Polyvinyl Chloride) & Anything Vinyl – Releases chlorine gas, which can corrode your laser and poison you.
- Polycarbonate (PC/Lexan) – Emits toxic benzene fumes and can catch fire.
- PETG (Polyethylene Terephthalate Glycol) – May release harmful fumes, depending on additives.
- Nylon (Polyamide) – Produces hydrogen cyanide gas, which is deadly.
Other Materials to Avoid
- Fiberglass – A mix of glass and resin, releasing toxic fumes and fine particles.
- Epoxy Resins (Cured or Uncured) – Produces hazardous fumes and fine dust.
- Foam (EVA, Polyurethane, Polystyrene) – Extremely flammable and releases cyanide or toxic hydrocarbons.
- Treated or Coated Wood (Plywood, MDF, Painted, or Stained Wood) – Contains adhesives and chemicals that release formaldehyde and other toxins.
- Chromium-Tanned Leather – Emits hexavalent chromium, which is highly toxic and carcinogenic.
- Anything with Unknown Coatings or Glues – If you don’t know what’s in it, don’t risk it!
Why is Plywood Bad for Lasers?
Plywood is made of thin sheets of real (or fake!) wood glued together. Some plywood is ok, but you need to investigate what kind of glue was used to make the material. If it has synthetic adhesives, you're in for trouble.
Plywood can also burn unevenly because of the layered structure, especially if the inner layers are harder wood. Also, thin inner layers could burn easily if you're not careful.
Burn, Baby, Burn...and Vaporize!
Lasers don’t just cut materials—they burn and vaporize them. That means anything you put under a laser can turn into airborne chemicals that you might breathe in. Even with a strong ventilation system, you don’t want to risk toxic gas exposure, fire hazards, or damaging your expensive laser machine.
If you’re ever unsure about a material, look up the MSDS (Material Safety Data Sheet) or check reputable sources like university laser safety guides.
Final Thoughts
Lasers are an awesome tool, but they aren’t magic wands—using the wrong materials can seriously harm your health and your machine. Stick to safe, natural materials and always err on the side of caution. If something smells awful, releases dark smoke, or seems off, stop immediately and check if it’s safe.
Got any materials you’ve tested and found questionable? Let me know in the comments!