You can make your own sidewalk chalk with the following recipe from Summer: A User's Guide by Suzanne Brown (Artisan, 2007, $19.95). Here's a tip: Try splitting this recipe into batches and make each a different color.

SIDEWALK CHALK

1. In a large mixing bowl, using a rubber spatula or large wooden spoon, combine the water, plaster of paris and paint. Allow the mixture to stand for five minutes.

2. Place the toilet paper tubes on a sheet of cardboard or baking sheet, open sides facing up, then carefully pour chalk mixture into the tubes. If there's any mixture left over, discard it in the trash – not down the drain.

3. When the chalk is just about dry, peel off the tubes and allow your chalk to dry thoroughly for about 1 to 1 ½ hours.