On Easter long weekend, we had six teenagers in the house. Thanks to Pinterest, I found this very cool idea, which worked out perfectly. (As a bonus, it involved the dads.) TIPS: The perfect poster paint/water ratio was half and half. It seemed to thin out the paint too much but ended up splashing in a more dramatic way on the paper.
Easter is over but this activity will work any time of the year! (Very good idea for a School Fair by the way.)