The ceilings of many homes and apartments are not painted, but instead are coated with a substance that has a bumpy texture. It looks like this:

This treatment is normally called a textured finish or an acoustic finish by builders, but most people refer to it as popcorn. This sort of ceiling treatment is popular for several reasons:



It keeps you from having to plaster and sand the ceiling. If you've ever done it, you know that plastering a ceiling is no fun.

It hides lots of imperfections in the ceiling. The ceiling is a huge, flat, uninterrupted and well-lit expanse. Any imperfection is immediately obvious. The texturing hides imperfections very effectively.

It helps eliminate echo in a room. If you have ever talked in a room before and after carpeting, you know what a big difference carpet makes on echoes. An acoustic finish is like carpeting the ceiling.

There are many different ways to put a texture on a ceiling, but the most common technique involves mixing some sort of lumpy aggregate -- either vermiculite or polystyrene -- with ceiling paint. The mixture is then sprayed onto the ceiling using a special spray gun like the hopper texture gun from Lemmer. It goes on in one coat, and once it dries (like normal paint), you're done!

These links will help you learn more: