We’ve seen Elisabeth Moss wear a multitude of sweaters, suits, and dresses—from the stuffy to the sleek—while portraying Peggy Olson on Mad Men. As the show ventures further into its final season (and 1969), the actress shares why she appreciates how the characters’ outfits have most recently evolved.

“I feel like the style has definitely gotten a little more comfortable and more linen and polyester,” she tells InStyle.com at the Elephant Crisis Fund Sunset Gala. And that’s good news for Moss, who prefers the synthetic fabric. “I know people don’t like polyester, but I actually like it. I like it better than wool. It is not summer yet, so talk to me when it gets a little hotter, but I prefer it to the wool suits and heavier garments,” she says. “It has a little bit of stretch, I like it. When they put me in that, I love it—I’m like ‘bring it on.’”

See More Photos: This Week’s Hottest Parties

Moss wore a Chloé jacket with a Chanel bag and Dior heels (above, left) to the gala, a fundraiser to raise awareness for and combat elephant poaching, which took place on Saturday in Malibu, Calif. And although the actress spends plenty of time in costume for the show, she doesn’t think that Mad Men‘s fashions have directly affected her personal wardrobe–at least not yet. “It hasn’t influenced my style at all, but the clothes are getting more similar to what we actually wear,” she says. “I’ll go for a fitting with my stylist and there are things where I could wear the dress and walk onto the show. There are more and more moments like that—the styles are merging as we get closer to this time period.”

Every week Mad Men costume designer Janie Bryant shares her thoughts on fashions seen in the show’s final season. Get her take on the outfits in our gallery!