We just finished painting the last three unfinished rooms in the house in a marathon three-week painting session. I did a much better job of not ruining any paintbrushes this time. It figures, since now we don't really need the brushes for future work.

Here is what I've learned about making paintbrushes last through more than one painting session:

• If you're using latex paint, wash the brush out every 20 minutes. This will keep it from getting what George calls "the Susanna effect": a ring of dried paint around the top of the bristles. When you're done, rinse it with water and a little dish soap if necessary. Hang pointing down to dry so the top of the handle doesn't rust.
• If you're using oil-based paint, soak the brush in paint thinner every 30 minutes or so to keep the bristles clean. When you're finished, you can leave it in paint thinner overnight. If you're not going to be using the brush again for a while, clean it with paint thinner but don't squeeze all the thinner out of it. Wrap the head of the brush in plastic wrap, wrap the whole thing in tinfoil, and store it in the freezer. The brush will still be good the next time you want to use it.