Exclusive! Go Behind-the-Scenes at New York Fashion Week: A Day in the Life of Zac Posen

"The day of the show is electrifying. We're still putting the finishing touches on the garments."

"The emerald green gown is the highlight of the collection, so it needs to be perfect." Last-minute alterations were actually made on the gown just moments before the show. The gown was pinned and stitched on to the model, because it had to fit perfectly.

"A look at the final hair and makeup test. The beauty was inspired by Old Hollywood glamour: retro bobby-pinned waves, winged eyes, and classic red lips." Hair by Odile Gilbert for Kerastase Paris; makeup by Kabuki and the MAC Pro team

"At the walk-through-watching my girls go down the runway is always cathartic for me."

"We're finalizing the run of show, with more casual (but still glamorous) daytime looks in the beginning and our dramatic ballgowns at the end."

"Final looks! There will be two shows tonight, one at 6 PM for buyers and friends, and a smaller one for press at 7 PM."

"Backstage love after the first show-everything went perfectly."