Since 2007, the retro alchemy of AMC’s “Mad Men” has been zapping viewers back to the 1960s. (Its believed-to-be final season begins in early 2014.) The show’s canny blend of character studies and drama relies heavily on the work of costume designer Janie Bryant, who has garnered both critical acclaim (multiple Emmy nominations) and widespread fashion influence via her way with skinny ties and wiggle dresses. Bryant will discuss her work at a Smithsonian Associates event at 7 p.m. Monday. Following the presentation, guests can sip JFK-era highballs and see her costume sketches.

What’s your design process like?
Costume is about telling a story of a character through what they’re wearing. For the most part, I do custom garments by designing them, having them built or buying vintage pieces.

How do you use costumes to express these characters?
With Don Draper [the dark lead of the show played by Jon Hamm], he’s always the same in dark suits. They’re his armor. But Peggy Olson [a young advertising pro played by Elisabeth Moss] had an interesting Season 6. She’s expressing her increased freedom via things like miniskirts and, in the last episode of the season, a pants suit.

The costumes on “Mad Men” have changed so much as the show has moved through the ’60s. Which year was your favorite to work on?
I love variety, so it’s all good. The Camelot period in the early 1960s was so idyllic and romanticized. But the clothes in the late ’60s got looser. I love the grooviness.

Why do you think the era appeals to you and other people still?
I like that, in the ’60s, there was still a dress code. People felt that it was the right thing to do to look your best.

Any tips on vintage shopping?
Make sure the seams are strong. And look for stains, sun damage or cigarette burns. Check the smell, too — sometimes things have been in mothballs for years.

Is it OK to alter vintage garments?
It depends on your sentimental attachment to them! My mother gave me her wedding suit, and I hemmed it, and now it’s a regret of mine. And on the show, I try not to cut anything, but sometimes I have to. It’s all about telling the story.

How can I wear vintage and not look, well, like an extra for “Mad Men”?
It’s about having that one vintage piece and doing modern hair, makeup and shoes.