CO2 Photo Engraving
CO2 photo engraving on wood, leather, slate, and Norton-white tile produces dramatic results when image prep and dithering are right. The wood grain interacts with dither patterns in a way fiber on metal doesn't, get that working for you, not against you.
Best CO2 photo substrates
- Maple: light tone, even grain. Best contrast for portraits.
- Cherry: warmer tone; fine grain. Premium for skin-tone portraits.
- Walnut: dark base; only suitable for mostly-light photographs (overexposed feel).
- Veg-tanned leather: beautiful tonal range; mask before engraving.
- Slate: instant white-on-black contrast. Amazing for monochrome portraits.
- Norton white tile: black-on-white, smoothest finish. The "magazine print" look.
Image prep workflow
- Source quality: 600+ DPI at final size. A 6×8" portrait needs ~3600×4800 pixels.
- Convert to grayscale in Photoshop / GIMP / Affinity.
- Levels adjustment: drag black point and white point inward to anchor pure 0 and pure 255.
- Brightness/contrast: bump contrast +20 typical. Helps the dither distinguish skin tones.
- Unsharp mask: radius 2-3px, amount 50-80%. Sharpens detail without grain artifacts.
- For wood: shift the curve slightly to lighten midtones, wood burns dark fast.
- For slate / Norton tile: shift midtones to darken, light areas need to ablate paint completely.
Dither selection by substrate
| Substrate | Best dither | Why |
|---|---|---|
| Maple, cherry, basswood | Stucki | Smooth gradients work with wood grain |
| Walnut | Jarvis or Atkinson | Lighter dither preserves light areas |
| Slate | Jarvis | Smoothest contrast on hard substrate |
| Leather | Stucki | Tactile gradients, classic photo look |
| Norton white tile | Jarvis | The community standard for tile portraits |
| Acrylic (frosted) | Atkinson | Light touch, preserves transparency feel |
Settings: CO2 photo (35-50W RF tube, 2" lens)
| Substrate | Speed | Power | DPI / Interval |
|---|---|---|---|
| Maple portrait | 350-450 mm/s | 15-22% | 318 DPI / 0.08 mm |
| Cherry portrait | 300-400 mm/s | 18-25% | 318 DPI / 0.08 mm |
| Walnut portrait | 300 mm/s | 22-30% | 318 DPI / 0.08 mm |
| Slate | 300 mm/s | 22-30% | 318 DPI / 0.08 mm |
| Leather portrait | 450 mm/s | 15-22% | 318 DPI / 0.08 mm |
| Norton white tile | 300 mm/s | 22-28% | 423 DPI / 0.06 mm |
Mask before engraving
Apply painter's tape (3M ScotchBlue 2090) over the engrave area BEFORE running. Smoke and ash settle onto the surface during the engrave; the tape catches it. Peel after, instant clean engrave. This is THE pro tip for CO2 photo on wood.
Pre-engrave test on a 30×30mm corner
Always run a small corner test of the image first. Verify:
- Contrast envelope is right (no fully-black blobs, no fully-white voids).
- Dither pattern reads cleanly (not muddy).
- Skin tones look natural, not splotchy.
If the test is wrong, adjust source image levels or change dither. Run another test before committing to the full piece.