I have a hallway which was painted many years ago, using a HVLP (vacuum cleaner) sprayer. The paint is a "spatter", containing at least 2 or 3 different colors. I would like to duplicate this effect. I am told that the effect was created by putting both oil-based and water-based paints in the cup, and allowing them to separate while painting. Does anyone know of this technique, and if so, how I can learn to produce it?