It’s well known about doing titanium dioxide… which is white… on white tile. So coverage can be a little finnicky to get right. However, you can just add a little bit of food colouring and viola, you can doublecheck your coverage.
8 ounces 91% IPA + 3 tablespoons titanium dioxide powder, and food colouring to taste
Shaky shaky… it’s pepto 
shoulda went with green.
Coat the tile, the colour lets you see if you missed any spots.
Take ~30 seconds infront of a fan to dry it, ignoring the touch mark.
Toss it on the machine and run it! Snapmaker A350 with 10W laser, 300DPI, 2000mm/m, 60% power, stucki.
Finally give it a wash and all the dye is gone! (ignore the darker part at the bottom, windows decided it was a good time to reboot for updates in the middle of the engrave, so I loaded it onto the USB drive and restarted it)
There you go. An easier way to ensure full coverage on your tile.