Engraving Slate on the Ray5 20W
laserray5slateengravingsettings
Slate engraves beautifully — the laser ablates the surface leaving a bright white/grey mark on the dark stone. Great for coasters, plaques, signs, memorial pieces.
Why Slate Works
Slate is a fine-grained metamorphic rock. The laser creates microfractures and removes the dark surface layer, exposing lighter subsurface material. No chemical change — purely physical ablation.
Settings
| Speed | Power | Passes | Result |
|---|---|---|---|
| 3000 mm/min | 50% | 1 | Light grey mark |
| 2000 mm/min | 70% | 1 | Standard white mark |
| 1200 mm/min | 85% | 1 | Deep bright white |
| 800 mm/min | 100% | 1 | Very deep, maximum contrast |
| 600 mm/min | 100% | 2 | Engraving with raised texture feel |
Starting point: 1500 mm/min, 75%, 1 pass. Adjust from there.
Process
- Clean the slate — dust and oils affect result. IPA wipe.
- Mark flat face — engrave on the smooth cleft face, not rough back
- Focus exactly — stone surface must be at focal length
- Run a test — always test a corner first. Each slate piece varies.
- Air assist — reduces dust buildup on lens
- Brush off debris — dry brush after engraving, then damp wipe
Design Tips
- High contrast designs work best — thin lines, fine detail engrave well
- Photos — convert to high contrast B&W, use Threshold mode at ~140
- Text — minimum 10pt font, bold fonts read better
- White areas in design = engraved = white on slate
Troubleshooting
| Issue | Fix |
|---|---|
| Mark too faint | Slow down or increase power |
| Mark too dark/rough | Speed up or reduce power |
| Uneven marks across piece | Slate not level — shim underneath |
| Dust on lens after | Add air assist, reduce passes |
Sealing
After engraving, apply a light coat of matte clear sealer or lacquer to protect the engraved area and increase contrast. Wipe-on polyurethane works well.
Slate Sources
- Craft stores (Hobby Lobby, Michael's) — small coaster blanks
- Amazon — slate coaster sets, tile sets
- Local tile stores — offcuts often free or very cheap
- Roofing suppliers — authentic roofing slate in large sheets