Old paint on ceiling.. best way to hide it???
 

The previous owners of my home were quite sloppy when they painted! I have white popcorn ceilings and in my childs room, the lilac wall color is on the ceiling portion. I dont want to paint the entire ceiling, but is there a product I can use to hide it? Would my latex primer work?? The hard part is not knowing what is on there now and I would not want to touch it up and it be noticeable.

Just go to a paintstore and pick up some white/offwhite color chips. Use these to get a decent match with the popcorn ceiling. Then you can touch up & make those lilac paint spots disappear. You're never going to get a perfect match, but, hey, white spots are better than looking up at purple spots on the ceiling. The other option is to paint the whole ceiling & that's quite a chore doing popcorn.