Mah-Jing Wong

Kicking off the season with an unconventional materials challenge, Heidi and Tim welcome the designers at a season 15 launch party.

The designers must create an outfit to flatter all body types, and the challenge proves to be more difficult for some than others. Guest judge Nina Dobrev joins.

In Project Runway's first Blacklight challenge, the designers have to create a look that sparkles not only in daylight, but under blacklights on the runway as well. Anxieties rise when the unusual materials leave many of the designers in the dark. Jaime King joins the judges this week.

In the Heidi Klum Swimwear challenge, the designers create their own fabric to use in designing a stylish swimsuit.

Actress and singer Sabrina Carpenter joins the judges' panel in the season's first team challenge, the designers exercise their business savvy when they pitch their collection ideas.

The exhausted designers are whisked away to Universal Studios Orlando to recharge their batteries with a roller coaster or two, and are challenged to find inspiration from their experience.