Sometimes, the challenges on "Project Runway" are pretty straightforward. But then there are other challenges so hard that we're surprised a winner could even be declared. Whether due to the limitations of the challenge or the outlook of the judges, these challenges were among the toughest in all of "Project Runway" history.
Flag Challenge (All Stars)
The designers were tasked with creating a dress inspired by the flag and fashion aesthetic of countries like India, Papua New Guinea, and the Seychelles.
But despite being told explicitly to incorporate the flag colors and national identity of their country of choice, the judges seemed to be judging by a totally different set of criteria. Isaac slammed Mondo's dress for its obvious color ties to the flag on the back of his look, while Mila got sent home for her asymmetrical dress. It seemed like the judges didn't really know what they wanted, and that made the runway judging process all the more painful.
Postal Service Challenge (Season 1)
Tasking high fashion designers with revamping the USPS uniforms was a flawed challenge. With little room for personal expression, the designers had to create something functional and tame. It was a boring and stifling challenge. Kara Saun won, the first designer in the show's history to win two challenges in a row.
Lingerie Challenge (Season 2)
Striking the balance between innovation and practicality is hard when it comes to lingerie, and almost every team of designers struggled with creating something that was aesthetically pleasing. After all, they couldn't just send a bra and panty set down the runway: it had to have some sort of signature flair. Santino's team created goofy Bavarian-inspired looks with way too many ruffles, while Daniel Franco's team created looks that were too matronly and he was sent home.
Couture Challenge (Season 3)
Haute couture looks can take months to make: the designers obviously didn't have that much time. With a budget of $375, they had to create an evening gown using haute couture techniques like intricate beading and hand-sewing. Vincent couldn't hack it, and got sent packing.
Car Challenge (Season 5)
Over the years, there have been plenty of challenges that used unconventional materials, but none quite so strange as the challenge where the designers had to scavenge car parts and upholstery to craft their looks. With only one day to complete the challenge, Keith was driven off and Leanne took a victory lap.

