Vivienne Westwood at the end of the Spring/Summer 2008 ready-to-wear collection show in Paris, October 2007 (Pierre Verdy/AFP/Getty Images)

An exhausted woman is moaning in a chair. She doesn’t want to be interviewed for a film about her life or asked the same questions for the millionth time. “Let me just talk and get it over with,” she demands. Thus the first few frames of Lorna Tucker’s Westwood: Punk, Icon, Activist kick off with the raw honesty of its subject, designer Vivienne Westwood, a woman unafraid to look mean on camera and to answer mealymouthed comments with a blunt, “It’s crap.”

Tetchily sizing up her own fashion collection or recalling her dreary early years, Westwood is one tough biscuit. The film calls on the usual fashion suspects to shower accolades on the clothing designer, but it’s best when it leaves the fawning Andre Leon Talleys and Kate Mosses behind and lets Westwood talk about Westwood. “I have spatial intelligence. At the age of five, I could have made a pair of shoes.” From her working-class youth, Westwood felt like “a knight,” a crusading figure who had to fight to transcend her limits: “I knew I was stupid, and I had to discover what was going on in the world.”

As a newly divorced schoolteacher in the mid-1960s, Westwood took up with future pop culture impresario Malcolm McLaren. Together they established a succession of boutiques in the 1970s that featured Westwood’s distorted, chained-draped and oddly stenciled clothing.  Shop assistants Johnny Rotten and Steve Jones formed a band, the music followed the clothes, and the Sex Pistols briefly captivated the world. According to Westwood, “We invented punk.” Footage from the era captures Westwood riding the raw energy, but she has clearly moved on. “Really, have I got to talk about the Sex Pistols?” she complains. Bu then she does, to withering effect: “Johnny Rotten was quite a phenomenon. He hasn’t changed from being that phenomenon, unfortunately. He should have changed to something else by now.”

Westwood’s work is unpredictable, off-the-wall, and ecstatic. Scholars at the Victoria and Albert Museum discuss her fashion designs in elevated terms; Westwood simply says, “Everything I design has a story…That’s why my clothes are timeless.” After rejecting and ridiculing Westwood for years, the British fashion establishment finally accepted her as a leader on her own terms, with honors even presented from the queen. The punk hell-raiser is now Dame Vivienne Westwood, if you please.

Westwood appears to have some prickly estrangement with her two sons that the film skirts around. Buyers of her expensive pieces may not be pleased to know that her much younger Austrian husband—a former student of Westwood’s—does much of the designing. And the film touches on her social activism in the most cursory way possible. Still, Westwood is worth the view of this very English character hard at work, cutting through the bullshit, and pursuing her own vision.