What is OK to cut?
In general, materials that absorb the deep infra-red beam (10um) that the CO2 laser puts out are most affected.
- Organics such as paper, wood, and organic fibers absorb strongly and can be cut and engraved. Leather and wool often give off noxious odors.
- Wood and wood products like plywood, masonite, and similar. Variable results are reported depending on what adhesives are used to make up the wood products.
- Paper, cardboard, etc.
- Fabrics and felt
- Leather, which may require special dance steps like wetting, and may stink
- Glass absorbs, and can be etched easily. Your K40 will most likely engrave but not cut through ordinary glass
- Stones generally absorb and can be etched.
- Plastic or paint coated metals can be marked, but this amounts to burning off the coating under the laser. Anodized and dyed aluminum can be marked fairly easily; this amounts to burning the dye out of the anodized layer.
- Plastics can in general be melted or burned by the K40, but the results depend heavily on the exact materials.
- Acrylic (plexiglas, perspex, etc.) cuts easily and nicely
- Some plastics only melt and discolor.
- Plastics and adhesives in composite materials may give off toxic or corrosive gasses.
- ABS to some degree. While ABS gives off some hydrogen cyanide (HCN) when lased, it gives off small amounts; it also gives off CO and styrene gas, which is also somewhat poisonous. Use good ventilation.
- Marking bare metals needs special coatings to absorb. Cermark is commonly used. Dry moly lube spray has been used as an alternative to Cermark.
What should I stay away from?
Should not burn
There are certain materials you should not burn in your laser. PVC (polyvinyl chloride) releases hydrogen chloride (which forms hydrochloric acid in water) as it burns. Many other materials involving chlorine in the chemical makeup do too. Some materials release HCN (thatâs hydrogen cyanide!) gas as they burn.
In general, plastics with Chlorine or Florine in them, such as PVC and PTFE (Teflon), can give off poisonous gasses.
If you arenât sure about any particular material, ask for a Safety Data Sheet (SDS) (formerly MSDS or Material Safety Data Sheet) from the vendor, and check it for combustion products.
Cannot burn
Other materials you cannot burn in your laser. Materials that reflect deep infrared are not very affected, and the reflected beam can be dangerous to eyes and skin, as well as damaging the laser lens.
In general, bare metals generally reflect and canât be cut with a typical hobbyist CO2 laser.
- Much more expensive YAG lasers are more typically used for industrial metal laser cutting, often with thousands of times more power than a K40.
- Industrial free gas CO2 lasers hundreds of times more powerful than the closed system laser tubes can cut metal, which is why you will see vendors offering CO2 laser cut metal; they may be using 10,000W or more, not 30W or so.
- RF-pumped CO2 lasers can also cut metal when using an oxidizing gas assist even in the range of 100W, because that is an averaged power output; they output brief pulses of much higher power that gets the metal hot enough to burn in a stream of oxygen.
All three types of lasers described here for cutting metal are tremendously more expensive than the hoobyist-accessible closed-tube CO2 lasers.
Materials Table
This material was gathered from the web in the recommendations of either laser manufacturers for use with their CO2 lasers, or from user groups, maker spaces, or university advice/rules/cautions to student users. It is certainly not complete, and may contain errors, but itâs better than asking a fresh new question about âCan I cut/engrave XXX material in the K40?â every time. Please help enlarge and refine this list.
The materials are grouped by classes:
- O = organics
- P = plastics; yes, I know most plastics are technically organic, but for lasers, theyâre special
- I = inorganic, or mineral but not metals
- M = metals
| Material | Class | Engrave | Cut | Cautions | Why/Notes |
|---|---|---|---|---|---|
| Organics | |||||
| Cardboard, corrugated | o | Y | Y | Flames! | |
| Cloth | o | Y | Y | ||
| Cork | o | Y | Y | ||
| Cork (composite) | o | Y | Y | caution | Adhesives may cause poor results |
| Fabric (natural, not poly) | o | Y | Y | Synthetics are woven plastics. | |
| Felt/cloth/cotton/hemp | o | Y | Y | Wool felt stinks | |
| Leather | o | Y | Y | Stinks!! | No, really, it stinks horribly. Dyes with chromium can produce toxic fumes |
| Leather/Suede | o | Y | Y | Stinks!! | Note: artificial leather is PVC or PU; beware of chromium-based dyes |
| Matte Board | o | Y | Y | ||
| MDF/Engineered woods | o | Y | Y | caution | Adhesives may cause poor results |
| Mother of Pearl | o | Y | Y | ||
| Paper | o | Y | Y | ||
| Paper, card stock | o | Y | Y | ||
| Pressboard/chipboard | o | Y | Y | ||
| Woods (general) | o | Y | Y | ||
| Solid Wood | Y | Y | |||
| Plywood/Composite woods | Y | Y | caution | Adhesives may cause poor results | |
| Wood Veneer | o | Y | Y | ||
| Plastics | |||||
| ABS (Acrylonitrile butadiene styrene) | p | Y | ? | Ventilate well | |
| Acrylic/Lucite/Plexiglas/PMMA | p | Y | Y | Good results usually. Can give nice polished edges. | |
| Coroplast (âcorrugated plasticâ), made from polypropylene | p | Y | Y | Flames! | Reputed to catch fire easily. |
| Delrin (POM) | p | Y | Y | Toxic | Formaldehyde gas |
| Depron (EPS) foam | p | Y | Y | ||
| Gator foam | p | Y | Y | ||
| EVA foam | p | Y? | Y | ||
| Kapton tape (Polyimide) | p | Y | Y | ||
| Mylar (PET) | p | Y | Y | ||
| Nylon | p | Y | Y | ||
| Polycarbonate (Lexan) | P | ~ | ~ | Poor results | Melts and discolors, not clean |
| PETG (polyethylene terephthalate glycol) | p | Y | Y | ||
| Solid Styrene | p | Y | Y | Flames! | Catches fire easily |
| Teflon (PTFE) | p | Y | Y | Toxic fumes; birds are particularly sensitive. | |
| Thin Polycarbonate/Lexan Sheeting (<1mm) | p | Y | Y | Works better than thicker | |
| PVC (âvinylâ) | P | Y | Y | Toxic | Toxic/corrosive HCl released, eats machines and lungs |
| Polyurethane | P | Y | Y | Toxic | Releases hydrogen cyanide (HCN) |
| Kevlar | P | ~ | ~ | Toxic | Releases hydrogen cyanide (HCN) |
| Inorganics | |||||
| Carbon fiber mats/weave | I | N | Y | ~ | Non-epoxied mat, weave only |
| Ceramic (e.g. decorative tile) | I | Y | N | ||
| Corian | I | Y | N | Corian is powdered stone in resin | |
| Fiberglass | I | Y | N | ||
| Glass | I | Y | N | ||
| Magnetic Sheet | I | ? | Y | ||
| Marble | I | Y | N | ||
| Marble, Stone, Soap stone, Granite, Onyx. | I | Y | N | ||
| Melamine | I | Y | Y | ||
| Rubber | I | Y | Y | Varies | Some rubbers have chlorine, like vinyl |
| PCB (fiberglass, FR4, etc.) | I | ? | ~ | Varied reports | |
| Metals | |||||
| Bare Metals in general | m | N | N | Use Cermark or molybdenum-bearing grease with engraving settings to mark many metals | |
| Aluminum | m | N | N | ||
| Anodized Aluminum | m | ~ | N | Laser can burn out the dye | |
| Brass | m | N | N | ||
| Stainless Steel | m | N | N | ||
| Titanium | m | N | N | ||
| Painted/coated metals | m | Y | N | Laser can burn away the coating/paint | |
Material Sources
Most cities have suppliers of plastic sheet, wood products and paper products. Use the internet and search for whatâs local to you, or for a mail order supplier.
Where can I find more information?
Some maker spaces and other sources have maintained lists. Note that not all lists describe all known dangers; for example, some lists do not recognize hazardous fumes from cutting fluoropolymers like PTFE (Teflon).