Wall meets ceiling painting
Paint the ceiling first and don't have a heart attack if you get a little on the wall.
Then you cut into the wall top with the brush, I usually use a two inch brush.
The key with popcorn ceilings is that you never know what you're going to get until you've started and it's too late, so it's best to be cautious to start out with.
Some popcorn ceilings have a bad habit of disintegrating if they get too wet with paint. Latex paint, particularly. It can get the popcorn damp and release it from the drywall on the ceiling. It's not a bad idea to start out with an oil primer and go VERY light with a roller. Otherwise, you can end up rolling the paint on, and having the popcorn roll off in big blotches. And that stuff is no fun at all to have to try to patch afterwards.
[This message has been edited by JayF (edited December 10, 2002).]