Who knew? From an art newsletter:
Chalking is another new trend:
Chalking is done with regular art chalks. The advantage of using chalk is that it washes right out. If you are going out for an evening you can choose any color of chalk to tip the ends of your hair, apply long streaks, or color your bangs. Just let your imagination be your guide. Of course, you don't want to get caught in the rain!
The procedure for using chalk on your hair is:
Fill a bowl with 1 1/4 full of warm water. Place you color choices of chalk into the bowl making sure they are covered with water. Leave them in the water for 5-15 minutes. The longer time will produce better results. The water will make the colors more vibrant.
Use a pair of plastic gloves and take the desired piece of chalk and highlight the desired hairs. This can be on the front, sides, back or bottom of your hair. You can make the color subtle or drastic. Let the chalk dry on the hair. It will wash out when you shampoo. Scrub your hair when you shampoo to remove all the color.