The tiles attached are white glossy ceramic wall tiles from home improvement store covered in spray paint.
The the pet pictures are done with a glossy black spray paint on a 6x6 tile.
The tile with the couple in the loft door is done with a Rust-oleum brand spray paint, primer and paint in one. The color is Oil Rubbed Bronze. The tile size is 9 x 12.
After spray painting I let the tiles dry for a day. I processed my pictures through PhotoGrav, then through my 30 watt laser, I ran them at 30% power and 80% speed at 1000 dpi.
I find it far less annoying to ruin a $1 tile than a $10 piece of granite.
The pet tiles where my first try.
The idea was not originally mine. I got the basics of it from the project files on LaserU.com.