K40 CO2 Settings & Speeds

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Buy the K40 CO2 — check current price & availability

Engrave from the BACK side for a clean mirrored result.

Cast acrylic cuts cleaner than extruded.

2 passes at 35W.

2 passes at 35W for clean cut.

Apply Cermark or white acrylic paint, let dry, laser, wipe off.

Thick bamboo — engrave only.

K40 cuts leather well at 65%. One pass for up to 3mm thickness.

Plywood varies — 2 passes at 85% covers most 3mm stock on K40.

Cork cuts cleanly at 40% on K40. No air assist.

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Bamboo is dense — 2 passes at 85% on K40.

Basswood cuts in one pass on K40 at 70%.

Baltic birch in 2 passes on K40 — 35W is enough with air assist.

Cardstock at very low power. Watch for edge burning on tight curves.

Cardboard cuts easily on K40. Low power to avoid flare-ups — no air assist.

CO2 40W on stainless. Marking spray recommended.

CO2 40W on cork. Easy material.

CO2 40W on marble. Frosted white result.

CO2 40W cotton engrave. High speed.

CO2 40W cuts foam board in one pass.

CO2 40W on 3mm bamboo. Single pass.

CO2 40W chipboard. Single pass.

CO2 40W cuts corrugated cardboard in 1 pass.

CO2 40W rubber stamp. Fast deep engrave.

CO2 40W denim engrave. High speed, low power.

HTV vinyl score cut on CO2 40W.

CO2 40W on faux leather. Single clean pass.

CO2 40W on 7.5mil mylar stencil.

CO2 40W on 6mm EVA foam. No air assist needed.

CO2 40W on acrylic felt. Clean cut.

CO2 40W on 80gsm paper. Near max speed, minimal char.

CO2 40W on 300gsm cardstock. High speed, low power.

LightBurn forum: K40 users report 250–300 mm/s at 8–9.5 mA (roughly 20–25% of a 40W tube) for anodized aluminum raster engrave. K40 Whisperer equivalent is ~6–8 mA on the dial. Black anodize works well; violet/purple anodize may not absorb the 10.6µm wavelength cleanly. Stock K40 typically has no air assist. Source: forum.lightburnsoftware.com/t/engraving-anodized-type-ii-aluminum-k40-laser/38334 + funinthefalls.gitlab.io/k40/cats/Materials%20and%20settings

Very easy paper cutting for K40. Very low power — stay near 10% to avoid scorching fine detail on intricate cuts.

White engrave on slate. Invert image. K40 gives usable results on stone at this setting. Wipe with damp cloth after.

K40 is hugely popular for stamp making. 500 DPI for fine detail. Invert design — dark file areas engrave deep. Great consistent results.

CO2 works beautifully on leather. 22% is a starting point — K40 tube output varies significantly. Always test on scrap.

K40 cuts 3mm acrylic cleanly. Remove protective film. Without air assist edges may have slight melt — polish with a heat gun if needed.

K40 without air assist on MDF — watch closely. Good ventilation is essential. MDF fumes are heavy and unpleasant.

K40 Z-travel is limited — ensure precise focus. 200mm/s fill engrave at 30% gives good contrast. A digital readout upgrade helps with repeatability.

K40 stock tube output varies widely — run a material test first. 55% is a mid-point; adjust for your tube age and condition. Stock bed has no air assist.

Excellent contrast on natural cork. Cork chars easily — keep power low. Great for wine corks and coasters. No air assist — cork is lightweight and porous.

Apply dish soap or wet newspaper over glass surface before engraving — reduces thermal shock and produces frosted white finish. Wipe clean after. K40 CO2 engraves glass beautifully at low power. Cannot cut glass.

Clear acrylic cuts beautifully with CO2 — polished flame edge. Typical K40 setting: 5–7mm/s at 90% for 3mm clear in one pass. Remove masking immediately after cutting. Colored acrylic varies slightly — black needs a touch less, yellow/orange a touch more. Ventilate well.

What materials can the K40 CO2 engrave or cut?

The K40 CO2 has community-tested settings for 3mm Mirrored Acrylic, 3mm Clear Acrylic (Cast), 3mm Maple Plywood, 3mm Walnut Plywood, 6mm MDF, 6mm Baltic Birch Plywood, Ceramic Tile, Bamboo Cutting Board, and 40 more. Results vary by material batch, focus, and ambient conditions — always test on scrap first.

What settings should I use to cut 3mm Walnut Plywood on the K40 CO2?

A community-tested starting point is speed 16 mm/s, power 72% in a single pass. Always run a test cut on scrap to confirm before committing to your project.

What can a CO₂ laser like the K40 CO2 cut that a diode laser cannot?

CO₂ lasers can cut and engrave clear acrylic, glass (with care), fabric, and thicker wood more cleanly than diode lasers, because the CO₂ wavelength is absorbed by materials that are transparent to diode light. This makes the K40 CO2 more versatile for craft and production use.