I picked up some cheap glazed ceramic tiles at Home Depot. 22 cents per 3"x6". I had heard that using a mask and then painting before mask removal was the way to go. So, I wanted to give it a comparison go.
On the left is with masking, on the right is without. Frankly, it was easier to clean the excess paint off the unmasked one than it was to clean the little mask bits off the masked one.
And the results from the unmasked seem a little more consistent.
Full power @ 800 zooms or so.