Doing paint test number three today. Previous experiments used Krylon Fusion for Plastics, which had the unfortunate tendency to scrape off of high-friction areas on the unsanded, acetone-wiped doll. Today's paint is a plastic model paint I got from Hobby Lobby's Model Master's line.
Truth be told, what I'm testing with is primer, not paint. So far I've done two rather uneven coats with it, and though I held my breath while moving the joints between coats, I didn't immediately notice paint scraping off in huge chunks like I did with Krylon. The down side is that the paint does leave that gritty primer texture. I'm divided on this. Either I can hope that the matte coat (another Hobby Lobby plastic model brand, Testor's, I think) will cover that up and leave no descernable trace, or I can do a light dusting of Krylon Fusion on the larger spots that will be catching light before sealing.
I'm honestly not sure which method would be better. It might have been a good idea to try sanding down a doll and try the Krylon with it. I'm running out of body donors, though!
Edit: Decided to do a dusting of the sealant first, then see how it looks. Fingers crossed!