A Complete List of Laser Engraving Materials for OMTech K40+

The OMTech K40+ is one of the most popular CO₂ laser engravers for hobbyists, small business owners, and educators. Whether you’re creating personalized gifts, intricate signs, or custom labels, this 40W desktop engraver delivers precise, professional-quality results right from your workspace. But to truly make the most of your K40+, it’s important to understand which laser engraving materials it can handle safely and effectively. The material you choose impacts not only the quality of your engraving, but also the machine’s performance, maintenance, and safety. In this guide, we’ll walk through the complete list of materials compatible with the OMTech K40+, along with essential engraving instructions and material safety notes. Let’s take a closer look at what you can (and shouldn’t) engrave with your K40+.

A Complete List of Compatible Laser Engraving Materials

The OMTech K40+ can be safely used with the following materials:

Plastics

Laser Engraving Materials That Need to Avoid

The OMTech K40+ laser engraving machine CANNOT be used with the following materials or with any materials which include them: 

• Artificial Leather containing Hexavalent Chromium (Cr[VI]), due to its toxic fumes
• Astatine, due to its toxic fumes
• Beryllium Oxide, due to its toxic fumes
• Bromine, due to its toxic fumes
• Chlorine, including Polyvinyl Butyral (PVB) and Polyvinyl Chloride (PVC, Vinyl, Cintra, etc.), due to its toxic fumes
• Fluorine, including Polytetrafluoroethylene (Teflon, PTFE, etc.), due to its toxic fumes
• Iodine, due to its toxic fumes
• Metals, due to their conductivity and reflectivity
• Phenolic Resins, including various forms of Epoxy, due to their toxic fumes
• Polycarbonate (PC, Lexan, etc.), due to its toxic fumes

For all other materials, if you are unsure about its safety or laserability with this device, seek out its material safety data sheet (MSDS). Pay especial attention to information about safety, toxicity, corrosiveness, reflectivity, and reaction(s) to high heat. Alternatively, you can contact our support department for further guidance.

Instructions of the OMTech K40+ Laser Machine for Specific Materials

Ceramics

When engraving on ceramics, generally use moderate to high power. Using more loops rather than higher power and lower speed can help avoid cracking the material during work. Be mindful of the health risk posed by dust generated from ceramic engraving, especially for repetitive industrial applications. Depending on the material and the amount of work, a fan or even full ventilation system may be required to address the problem. Similarly, operators and others in the work area may need to use breathing PPE such as masks and respirators.

Glass

When engraving glass, generally use high power and low speed. As with ceramics, it can be helpful to run more loops at lower settings to avoid cracks. Care must be taken when engraving fiberglass and carbon fiber to avoid combinations of settings that produce a laser intensity great enough to damage the structural integrity of its component fibers, producing blurry marking. PPE should be worn to avoid exposure of the eyes, nose, mouth, and skin to the dust produced by working with either material, especially for repetitive industrial applications. Clothing worn while working with fiberglass should be washed separately afterward.

Leather

When engraving leather products, generally use low to moderate power at high speed. Natural leather should be engraved slightly slower and at slightly higher power than artificial leather. Be especially attentive to the possibility of fire, as well as the dust produced in repetitive applications.

Metal

CO₂ laser engravers should not be used for marking, engraving, or cutting metal. They are best suited for working coatings applied to a metal base, and care must be taken not to attempt work on the underlying metal itself. A variety of coatings specialized for CO₂ engraving are available, and the user should follow the instructions provided as the
parameters vary from product to product and metal to metal. Generally, work on aluminum coatings should be done more quickly at lower power, and work on steel coatings can be done more slowly at higher power.

Paper and Cardboard

When engraving various paper products, generally use low to moderate power and fast speed. Test samples from each batch as only small parameter differences can separate effects that are too light from those that burn through the substrate. As with leather, be especially attentive to the possibility of fire, as well as the dust produced in repetitive
applications.

Plastics

Plastics for engraving are available in many different colors and thicknesses and with many different coatings and surfaces. The majority of available plastics can be well engraved and cut with the laser. Plastics with a microporous surface seem to give the best result because less surface material needs to be removed. When engraving plastics,
generally use low power and high-speed settings. Marking and engraving with too much power or at too low a speed can concentrate too much energy at the point of contact, causing the plastic to melt. Among other problems, this may produce poor engraving quality, noxious fumes, and even fires. High-resolution engraving can cause the same
problem, so medium to low-resolution designs should be preferred for most plastics.

Rubber

Rubber’s inconsistent composition density causes slightly varying engraving depth. Testing various settings on sample pieces of your specific rubber is highly recommended for the best results. When engraving rubber, generally use a consistently high power setting and create your effects by varying the laser's speed. Microporous rubber materials require a significantly higher speed than standard rubber. Engraving any kind of rubber produces a considerable amount of dust and gas. Depending on the amount of work, breathing PPE and/or a full ventilation system may be required to address the problem.

Stone

When engraving various kinds of stone, generally use moderate power and moderate to fast speed. As with ceramics and glass, be mindful of the dust created (especially for repetitive industrial applications) and take similar measures to ensure the safety of users and others in the work area.

Textiles

When engraving textiles like cloth and fleece, generally use low power and fast speed. As with leather, be especially attentive to the possibility of fire and dust.

Wood

As with rubber, there is a huge variety of woods and testing your specific material is essential to get the best results. In general, wood with consistent grain and coloring engraves more evenly. Knotted wood produces uneven effects, while resinous wood produces greater edge contrast. Some softwoods like balsa, cork, and pine engrave well (albeit with low contrast) at low or moderate power settings and high speed. Others like fir suffer from uneven fibers that usually produce a poor effect no matter what you do. Hardwoods like cherry and oak engrave well at high power settings and low speed. Manufactured wood products can vary from brand to brand, mostly based on their glue
composition and abundance. MDF works well but creates dark edges when cut.

In addition to the risk of fire with any wood product, extra care must be taken with the fumes from the glue used in plywood and other manufactured woods. Some are too dangerous to work with at all, while others require careful ventilation and the use of breathing PPE for repetitive industrial applications. Wood toxicity should also be examined, as the dust from some natural woods, including oleander and yew, can cause nausea and cardiac problems in high enough amounts.

Material Safety Guidelines

• Users of this laser engraving machine are responsible for confirming that processed materials can withstand the heat of the laser and will not produce any emissions or byproducts either harmful to people nearby or in violation of local or national laws or regulations. In particular, do not use this device to process polyvinyl chloride (PVC), teflon, or other halogen-containing materials under any circumstances.
• DO NOT use high power settings at very low speeds when engraving highly flammable materials. Instead, use more repetitions of your design at low power settings to achieve a similar effect.
• Users of this laser engraver are responsible for ensuring that every person present during operation has sufficient PPE to avoid injury from the emissions and byproducts of the materials being processed. In addition to the protective laser eyewear described above, this may require goggles, masks or respirators, gloves, and other protective outer clothing.
• DO NOT ever use this laser engraver under any circumstances if the exhaust system is not working properly. Always ensure that the exhaust system can remove the dust and gas produced by the engraving process in accordance with all applicable local and national laws and regulations. Immediately stop use and clean or repair the system if the exhaust fan or vent pipe begins making more noise than usual or otherwise malfunctions. ONLY use this engraver when its air assist is working properly.
• Users must exercise special caution when working with conductive materials as the buildup of their dust and ambient particles may damage electrical components, cause short circuits, or produce other effects, including reflected laser radiation.

Conclusion

Choosing the right materials for your OMTech K40+ is the key to achieving consistent, high-quality results while keeping your workspace safe. By following the official material list and engraving recommendations, you’ll protect your machine, avoid unnecessary wear, and bring your creative ideas to life with confidence. If you’re ready to explore more engraving ideas and community tips, visit OMTech’s Learning Center or join the OMTech Facebook Community — where creators share real-world insights and inspiration every day.