Laser Engraving on Metal vs Wood vs Acrylic: Settings and File Requirements

How laser energy interacts with materials

Laser engraving is controlled material removal or modification. The same file and settings will not behave the same across materials.

Wavelength matters: CO2 is absorbed by wood/acrylic but reflects off bare metal; fiber is absorbed by metals.

Heat dissipation and vaporization/burn temperature determine how much energy you need and how forgiving a material is.

Wood: settings and file requirements

Wood is forgiving and provides good contrast, but grain and moisture change results.

For detail: use 250–500 DPI for photos, 150–300 DPI for text/graphics. Strong grain can hide midtones.

Wood often engraves better with stronger contrast and dithering rather than smooth grayscale.

• CO2 starting points (40–60W): light 15–25% @ 300–500 mm/s; standard 25–40% @ 200–400 mm/s
• Prefer fine-grained woods (maple/cherry/birch) for detail
• Masking tape can reduce smoke staining and visual unevenness

Acrylic: settings and file requirements

Acrylic can hold excellent photographic detail because it engraves cleanly without char.

Use cast acrylic for engraving (frosted white). Extruded acrylic often engraves with weak contrast.

Acrylic supports smooth grayscale gradients well; dithering is optional and stylistic.

• CO2 starting points (cast): light 10–20% @ 400–600 mm/s; standard 25–40% @ 300–500 mm/s
• DPI: 300–600 for photos; 500–600 for small high-detail engravings
• For backlit clear acrylic, invert images and test (counterintuitive)

Metal: settings and file requirements

Metal engraving depends on laser type. CO2 typically marks coated metals or uses marking compounds; fiber lasers can mark bare metal directly.

Metal has a limited tonal range. High contrast and dithering usually produce the most consistent results.

Vector lines often need multiple passes at lower power for better control and less heat distortion.

• CO2 + marking spray: often 80–100% power @ 50–150 mm/s; 300–500 DPI
• Fiber: anneal/oxidize vs ablate have very different parameter ranges—test per alloy
• Clean the surface (oil/oxide) before marking for consistency