It certainly was a good time to get into the hat business, says Pamela Roskin, one of the graduate-student curators of ''Lilly Dache: Glamour at the Drop of a Hat.'' Women often bought a new hat each season, and many bought three or four of them.

''A woman's best hat would be a Lilly Dache,'' Roskin said.

The first test of Dache's ingenuity came during the wartime '40s, when there were limits on materials and many women were going to work instead of lunch. It's also when the Dache Net, a hair net, debuted in drug stores.

A Dache snood, a covering for women's hair buns, appeared on the cover of a 1942 issue of Vogue, and by 1944 she was making work-friendly turbans and kerchief-style hats. ''They were fashion versions of the Rosie the Riveter look,'' Roskin said.

For the more formal hats that she continued to make, Dache turned to trimmings — such as lace and ribbon, which were not rationed — as the primary material for hats.

The postwar boom brought an opportunity for the hatmaker to tackle other parts of the wardrobe and she launched both a clothing collection and a fragrance. She and her husband, a top executive at Coty, were a marketing dream team, putting stylish women wearing Dache hats and outfits in the cosmetic company's ads.

The 1950s were a transitional period for hats. In the early years, hats became ultra dramatic and ultra elegant — a true status symbol, but by the end of the decade interest in hats began to wane.

Dache started to create hats that mimicked hairstyles: A cropped hat made of yellow-and-black feathers with a headband-style bow featured in the exhibit is a perfect example.

Young designer Roy Halston, who went on to be Jackie Kennedy's hatmaker of choice, had his first job with Lilly Dache in the late '50s. A pillbox hat was in the collection by 1959.

Hairstyles of the '60s greatly influenced the direction of hats. They were either very small or very large to accommodate the trend of women wearing their hair longer and looser.

Since she was the standard-bearer of her industry, her peers were understandably upset when Dache turned out to a big social event in the '60s without a hat on her head, according to Roskin. Dache explained that it simply was not all that fashionable to wear hats anymore and that she would start wearing wigs — which, of course, she also sold.

Dache retired in 1968 but kept her hand in the fashion business, licensing her name to menswear companies. She died in 1990, and in 2002 became the only milliner featured in the Fashion Walk of Style in the Garment District.