I used this technique a while back. I think Patti Behan gave it a proper name when she demo-ed it on her blog, but as I can't remember it, 'splat' will do.
I made this atc for the acrylics paint challenge on Saturday Workout.---
Stamps: Simple Expressions People 2; MSE Friends Always
Inks: Adirondack Dabbers Snow Cap, Butterscotch, Lemonade and Lettuce; StazOn Love Green; Adirondack Ink Lemonade; DI Spiced Marmalade
Extras: Prima Flower; Green Brad