Justin Timberlake is wearing William Rast Ben jeans with a New America T-shirt and blazer.

Making music and acting have been Justin Timberlake's passions for decades. Now, he can add a new accomplishment to his résumé—fashion designer. In 2005, Justin co-founded the William Rast clothing line with his childhood friend and business partner, Trace Ayala.

"We've always wanted to get into it," Justin says. "I think there was more actual apprehension for me because, in this day [and] age, you do something, you want it to come across genuine."

Take a tour of Justin's design studio. Watch

The name of the fashion line, which is known for its premium denim, is a tribute to two important men in their lives—their grandfathers. "Trace and I are huge fans of our grandfathers," Justin says. "William is my grandfather's first name, and Rast is his grandfather's last name. So we took the names, and put them together."

Today, Justin is wearing William Rast "Ben" jeans with a New America T-shirt, utilitarian shirt and a dark gray wool blazer.

Want to see more? Justin brought along a few of his favorite items from the spring 2009 collection!
A model wears William Rast's black leather jacket with studs and Jerri skinny jeans.

Justin says he loves to see women wear a mix of sexy and tomboy looks...a style his girlfriend, actress Jessica Biel, is known for. "She's obviously a huge muse for me and with the designers too," he says.

In keeping with this style, the first model is wearing William Rast's black leather jacket with studs and "Jerri" skinny jeans in Rosewood wash.

Every woman should have a good pair of jeans and a leather jacket in her wardrobe, Justin says.
A male model pairs the William Rast Ben jeans with a flannel shirt and optical wave wool blazer.

Over the years, Justin has become known for his unique sense of style. "I like mixing sort of a cleanup top with the rugged jeans and like a flannel with a blazer," he says. "Try it, guys. See what happens."

To illustrate his point, a male model pairs the William Rast "Ben" jeans with a flannel shirt and optical wave wool blazer.
A woman models William Rast denim shorts, a New America flag silk T-shirt and a green biker vest.

This model is wearing the Boyfriend denim shorts, a New America flag silk T-shirt and a ruffled, military green biker vest.

What's the inspiration behind these looks? "I'm inspired by our president, and I'm inspired by new leadership," he says. "I'm inspired by the world, and we're expressing it."
A man models Ben jeans with a William Rast leather jacket.

William Rast takes its denim very seriously. To get the creases for the line's "Ben" jeans just right, Justin says Johann, the head designer for men, wore the same pair of jeans for 18 months...without washing them.

Now, that design is a staple of the collection. This model pairs the dark "Ben" jeans with a William Rast leather jacket and New America flag T-shirt.
Ellen in Jerri skinny jeans and a mushroom leather jacket

Justin and Trace's clothes don't just look great on models and celebrities. Trace took to the streets of Chicago to recruit young men and women to model more looks.

Watch Trace scout for models around Chicago. Watch

During his search, he found Ellen! Now, she's backstage at The Oprah Show wearing "Jerri" skinny jeans in Hematite wash and a mushroom leather jacket with ruffles.
Prosper in Ben jeans and a black leather bomber jacket

Prosper was working in a clothing store when Trace approached him to model the "Ben" jeans with a utilitarian shirt and black leather bomber jacket.
Amanda in Jerri skinny jeans and a New America leather biker vest

Trace found Amanda walking down Chicago's Magnificent Mile. The designers dressed her in "Jerri" skinny jeans, a gray plaid flannel shirt and a New America leather biker vest.
Jacob in William Rast Ben jeans and a flannel shirt

Jacob was walking with Amanda when they were discovered. Now, he's modeling William Rast "Ben" jeans and a flannel shirt.
Ali in William Rast jeans, silk top and biker jacket

Last, but certainly not least, Ali Wentworth models the "Jerri" skinny jeans, a white silk top decorated with skulls and a blue leather biker jacket.

"You say these jeans are guaranteed to make women's butts look good," Oprah says.

"I stand by that statement," Justin says.

What's the secret? Justin says it's all about the jeans' yoke—the material between the waistband and pockets. "More high-waisted jeans have more distance between the yoke and the waistband," he says.

"You are all up in my yoke," Ali jokes.

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