What happens when you laser slate
Engraving slate removes or changes the dark surface layer, leaving a lighter grey mark. There’s no cutting involved, so it works on lower-powered diode machines as well as CO2.
Designs that work
- Bold text and line art — names, dates, house numbers, simple illustrations.
- Photos need dithering; high-contrast images work best because slate gives a limited range of tones.
- Leave a margin: natural slate edges are often uneven.
Steps
- Wipe the slate clean and let it dry.
- Check the blank sits flat on the bed. Many coaster blanks have a slight bow — shim it level if needed.
- Focus on the top surface.
- Run a test grid on the back of one coaster or on an offcut. Look for an even, pale mark without flaking.
- Engrave, staying with the machine.
- Wipe off any dust with a damp cloth, then add cork or felt pads to the underside.
Finishing touches
A light coat of food-safe mineral oil darkens the unengraved slate and increases contrast. Let it soak in, then buff off the excess.