Friday, July 6 — “Katy Perry: Part of Me” is showing around the world in 3D. But for Shawn and Claire Buitendorp, the real thrill comes from 2D — as in Two Dresses. The 22-year-old twin sisters created two of the eye-popping outfits Perry wears in the documentary, which chronicles her “California Dreams” world tour.

The Buitendorps checked out the film on Thursday (along with their older sister, Erin, a City Pulse Pulsar judge). They didn’t have to wait very long to see the first of their creations on the screen. Their pink, conversation-hearts-themed dress shows up less than 10 minutes into the movie; another gown, which looks like a hot fudge sundae — complete with a maraschino cherry hat — also shows up at regular intervals.

“I’d say our pink dress was in there four times,” Shawn Buitendorp said. “The hot fudge more like six, seven, eight? When she’s backstage is when you’ll see them. She doesn’t wear them onstage, but she wears them when she does the meet-and-greets with the fans.”

The hot fudge outfit even appears during one of Perry’s make-out scenes with her now-ex-husband Russell Brand. “We were marveling about that,” Shawn Buitendorp said. “Apparently, he likes her in it, too.”

The Buitendorps presented Perry with the conversation-heart dress on June 28 last year, when they met her backstage at The Palace of Auburn Hills. The hot fudge number was sent over to Perry’s staff on Nov. 16, when Perry was performing at Madison Square Garden and the Buitendorps, who had recently graduated from Lansing Community College, were doing an internship with designer Betsey Johnson in Manhattan.

“It took a good two months” to complete the hot fudge dress, Shawn Buitendorp said. “We were actively working in our internship at least 14 hours a day, and so we’d come back home and sew things until 1:30 in the morning. We didn’t have as much time to work on it as we hoped, so we worked when we could.”

It also turned out to be an educational process since the Buitendorps wanted to use latex as a major part of the outfit. “(Perry) actually wears a lot of latex, but Claire and I had never seen a dress with latex and other fabrics combined. So we had to learn: Can you sew latex? Do you have to glue it to other fabrics?”

The answers to those questions came through trial and error.

“If you try to sew latex, the stitches don’t hold together. You have to glue latex to latex and glue it to other fabric, so it’s kind of a mesh of the two. We had a lot of fun — we went to the hardware store and found a lot of different adhesives.”

They’ve sent Perry a third dress, which Shawn Buitendorp describes as having “more of a futuristic feel. It’s all white with Swarovski crystals; maybe more of a wintry feel.”

The Buitendorps are planning to return to New York in September to assist Johnson with preparations for her next show. Ultimately, however, they have set their sights on becoming stagewear designers.

“When we were looking through the end credits at all the members of the wardrobe team, we saw names like Jeremy Scott and The Blonds and Johnny Wujek — all these people that are famous to us,” Shawn Buitendorp said. “And Claire and I had a dress in the movie with all of those wonderful names. We have an outfit on the same screen as they do.”

A Teenage Dream come true? “Yeah, it’s quite a victory for us,” Claire Buitendorp said.

Visit Claire and Shawn's blog here.