Many also are highlly individualistic and may choose to die their hair interesting colors, cut it it strange ways, or dress in a rather offbeat manner. Many also started various trends (such as wearing Converse shoes) before they became mainstream.
Some are into theater or the performing arts. They are sort of a high school version of bohemians. (meant in the nonconformist sense of the word)
NOTE: (not at all to be confused with emo kids, as this is a totally different idea, though some art kids are emo and some emo kids are artsy in nature.)