The immediate response to the idea of Chris Rock making a movie about 'Good Hair' has to be to laugh. And for about 98 per cent of this film there are more than enough laughs to go around. This movie, as might be expected, is about black women's obsession with hair. The movie opens at the Bronner Bros. Intl. Hair Show in Atlanta, the world expo of hair which attracts thousands of people every year. Women - but especially black women - Rock says, are obsessed with hair. Rock probably started this movie on a humourous note, about how comically crazed women can get about what's on top of their heads. But his research ended up revealing a lot of the not-too-pleasant side of the industry. For example, the obsession African-American women have with "relaxing" hair to make it more beautiful and "white." The chemical used in this "relaxing," sodium hydroxide, is highly toxic. A lab demonstration shows it can eat a pop can in a matter of hours and has been known to burn women's scalps. It's even used on kids. Not surprisingly this industry is worth billions of dollars. And Rock's documentary shows just how much women will spend for ideal hair, not just for relaxing but for "weaves" or extensions. The film also reveals where human hair comes from - India, and a Hindu ritual where women, often asleep, have their hair shaved off - as an offering to the gods! And the costs of weaves are astronomical. Black women can spend thousands each year on hair products. Chris Rock's Good Hair is a comedy all right. But it's a first-rate documentary about the hair products industry, the exploitiation of women's obsession, and the displacement of money when many have trouble putting food on the table.