"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.
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!