Mr. Timberlake’s name was kept off the label to avoid the overt appearance of cashing in on his celebrity, but he approves all of the designs and comes up with some of them. William Rast, named after two of Mr. Timberlake’s and Mr. Ayala’s grandfathers, began selling $180 boot-cut jeans at Bloomingdale’s and a handful of other stores. The idea was that the partners would perfect their basic designs before making a more ambitious fashion statement. Mr. Timberlake has been savvy about his image since beginning his solo career in 2002. He has successfully erased the taint of his adolescent romance with Britney Spears, and he transferred the stigma of an infamous wardrobe malfunction at the Super Bowl almost entirely onto his duet partner, Janet Jackson. He has worked with the stylist Joe Zee, the editor of Vitals magazine (now defunct), to transition his own look from a wardrobe of leather ei ght-ball jackets, gold chains and faded jeans to a more adult one of rakish fedoras, skinny monochromatic Dior suits and three-piece tweed suits from Yves Saint Laurent. Before the September release of “FutureSex/LoveSounds,” Mr. Zee said he flew to Los Angeles to present the singer with photo-collages to inspire his look for the album’s marketing, showing him pictures of classic Hollywood rogues like Frank Sinatra and Sammy Davis Jr.