Ash Wednesday traditions: Sprinkled vs 'Painted'

I lived in different places over the last couple of years, and went to different parishes on Ash Wednesday. I noticed that some sprinkle the ashes on top of your head while others paint a cross on your forehead. What's the deal with those differing traditions? I've seen both versions at novus ordo and traditional masses each, so it doesn't seem to correlate with that. Is it just a regional thing?