In order for the paint to stick, you must clean the tile. I used 90% alcohol and scrubbed for a few minutes. Acetone would work better, but I used what I had.

In a well ventilated area, paint the tiles. I layered the paint in the following order:

1. White (Bottom Layer)
2. Light Grey (Second Layer)
3. Dark Blue (Third Layer)
4. Black (Top Layer)

I waited about 15 minutes between layers, using a hair dryer between coats to speed up the drying time. Be careful to apply the paint in the same way for each layer, and do your best to ensure that the layers are the same thickness. I do this by spraying horizontal lines, and then vertical lines. I move quickly, spraying just enough paint to cover the last color.

Once the last layer is on, give it at least 12 hours to fully cure. You could do it sooner, the the paint will continue to off-gas until it is fully dry, and bad things could very well happen if you try to engrave it while it has not fully dried. 

If you have not already, open up the file in XCS. If the image looks funny, it is supposed to, it's inverted because our bottom layer is white. If the bottom layer was black, then the image would not need to be inverted.

There are two engrave layers, yellow and light blue. The yellow is the first burn and is 2 passes. The blue is a single pass at a lower power. I did the light blue layer because the paint was a little thicker than I intended and not enough white was showing through after the yellow layer was done, so I used another pass at a lower power to pull a little more paint off. If you only want to do the yellow layer, you can select the blue and then turn off the output.

You will also want to confirm the laser settings, what I use may not necessarily line up with what you need.

When you're ready, process the job, click start, and then the green button!

That's it, you're done!