Tim Gunn On His Project Runway Spinoff Under The Gunn: ‘I’m Beyond Excited!’

Lifetime launches its new fashion competition series tonight – “Under the Gunn.”

“I’m beyond excited,” show host Tim Gunn told Access Hollywood about the series premiere. “Honestly, until I see it premiere on Lifetime, I don’t think I can fully comprehend that it is happening.”

Tim explained the premise of his new show is a twist on the mothership, “Project Runway.”

WATCH: Tim Gunn: How Will He Celebrate The Premiere Of ‘Under The Gunn’?

“We take the parts that I love most about ‘Runway’: talented designers, fun challenges and mentoring, my role on runway, and we expand the mentoring aspect,” he said. “We bring back three ‘Project Runway’ alumni. They each mentor — in the beginning — four designers each in the work room, and in fact there’s a whole selection process. The first two episodes are dedicated to that, where the designers who arrive do a challenge in the workroom so that the mentors have a deeper understanding of what it is that they do and then I’m mentoring the mentors so I’m kind of the big daddy of ‘Under the Gunn.’”

Those three mentors are Mondo Guerra, Anya Ayoung-Chee and Nick Verreos. In addition to the mentors, there will be guest judges on “Under the Gunn,” including Heidi Klum, who appears in the season finale, and Macklemore.

“Macklemore was a fabulous judge. Fabulous. Does he know his fashion,” Tim said.

Asked what the Grammy nominee brought to his role as guest judge, Tim told Access, “an incredibly knowledgeable understanding of 21st century fashion. … I was really extremely impressed. And he and I had a whole discussion off camera about menswear.”

“Under the Gunn” premieres tonight at 9/8c on Lifetime.

— Jolie Lash