So the Home Depot is carrying a darker-substrate line of tiles from dal tile. They engrave a light grey color and take marker pretty well.
I got a 12” x 12” mosaic tile and cut the individual small squares out of the grid. They’re about 1.85” to a side and have a very slight texture to them.
After engraving, it’s slightly grey. I almost stopped there, I thought it looked pretty good.
I thought the color was a bit too saturated. Alcohol takes some of the color off…
And here is the somewhat less-saturated tile. Pleased with it.
El cheapo markers from amazon. 36 markers for $16. Not sure about long term quality but the price is way way better than sharpies.