The most significant outfit of the book escaped that fate: the long dress of soft grey wool jersey in which Ruth died, with a cobweb cashmere scarf her mother tucked by her departing daughter's cheek; both were cremated with her. Picardie's description of them is as fine and tender as the scarf; it, and the finale of the book, in which she accepts the ragbag quilt of existence, are excellent work. As is the entry on her South African grandmother, who protested in the 1950s against apartheid by donning a sash, or long gloves, or fabric flowers, all in black: Picardie gets exactly the action of, and reaction to, outrageous appearances. Hard to bring that off now that no self-presentation surprises.

However, the rest of the book is a disappointment: chic chick nonfic, written in a tone that drifts like voile. Picardie professes a lifelong passion for what she calls "fripperies" but lacks contexts for clothes, and her researches seem casual, too personal. She's all sensibility, all feeling, and not for the texture of stuffs, either. A day in the V&A library would have established the real origins of an inherited embroidered jacket, around which she creates a romance about her father's Eastern European Jewish ancestry. (I was going to write "she weaves a fantasy", but Picardie is vague about warp and weft - defining a selvage, the nonfraying margin of cloth, as a "raw-edged seam".) There are litres of blood and pages of Brewer's Dictionary of Phrase and Fable in the section on scarlet women, but no curiosity about when and how dyes were developed that made flagrant garb fashionable. The King James translation committee worked on the Bible at a time when cochineal red was the hot colour: 10 years later, they might have described smart sin incarnate as the blush pink whore of Babylon.

Again, in a chapter on women in white, Picardie quotes multiple Brontës, Dickens, Wilkie Collins and Emily Dickinson, but among literary flitting doesn't consider the history of blanched females, no mention of the millennia in which washable vegetable fibres were worn next to the body beneath unwashable daywear, or as a single layer of pure vulnerability at night, and no sense of the extraordinary fashion change around the mid-1780s - which lasted for the next 30 years - when women wore flimsy garments of the type that would previously been underlayers. (Miss Havisham's fouled nuptial raiment would have been judged as pornographic when Great Expectations was published in 1860.) Picardie discovers that one of her forebears earned enough through whitework embroidery in the 1820s to purchase an education, an intriguing fact, but she is only interested in the familial details and not in the whitework, that ostentatiously discreet needle art. She rounds up a crowd of artistic dress extras - besides the above mentioned, Woolf, Plath and Zelda Fitzgerald are much cited for their mad glamour. (But not Jane Austen - a woman far too knowing about how useful, and useless, is the whole clothes charade.)

What exasperates is that Picardie has the intelligence and, through a job on Vogue, the rare access, that could have made a work of couture quality of her very original idea. She was allowed into the Haworth museum storeroom to see Brontë dresses; she sat on Gabrielle Chanel's sofa; she interviewed Donatella Versace and Claude Montana (and insisted on confronting them about deaths in the family); yet all these are subsidiary to her own emotions or indeed any passing pair of party shoes with the proper label. And why did she not consider menswear, especially in her family, with the same nostalgia? A patched tweed jacket on its last journey to Oxfam breaks the heart harder than any frock.