A Green Card holder who is not a minor can file Form N-400, Application for Naturalization, to obtain US citizenship. Similarly, he must have become a permanent resident before five years and must have remained as a permanent resident in America for at least five long years.
Now, flat paint is (usually) a latex paint that dries without a reflective finish-that's it-the finish is smoother (imho) than chalk paint. Chalk paint really dries quickly and it has a rough texture to it after it dries. Many people use wax or poly-acrylic sealant on top of their furniture piece to keep the paint from peeling. So there ya go, my best explanation.
Chalkboard Paint is rated 2.2 out of 5 by 9. 1  Rated 1 out of 5 by Kg55 from poor coverage I used this to help a friend create a small chalkboard area in her back hallway. I tried to talk her into the roll on type of paint, but she was lured in by the the spray paint mode. I was worried about coverage, so I talked her into buying 4 cans. Good thing I did - the coverage was so poor (even over a sage green wall) that I had to use 3 cans for a 12 square area.