By Christina Cheddar-Berk, CNBC.com
Jason Wu Bandeau BikiniJason Wu, Alexander Wang and Chris Benz all added swimwear to each of their resort collections for the very first time this year.
Blame it on the tough retail climate, says Catherine Moellering, executive vice president of Donegar's Tobe unit.
"It's not totally surprising that we're seeing this," Moellering says. She notes many other designers are expanding their brands to other retail categories and cited Tory Burch, who recently entered eyewear category, as an example.
It's all about driving more volume and coaxing luxury shoppers to spend more, according to Moellering.
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But swimwear is tricky.
"It's not a lot of fabric to communicate the brand message," she says. "It's much easier to communicate what you're about with yards of fabric."
The shift to swimwear also speaks to the importance of a designer's resort collection.
Alexander Wang"It used to be a season that not a lot of people paid attention to, but it has become a bigger business," Moellering says.
Historically, resort collections were created for wealthy women who would travel to warmer climates during the winter, but now these pieces provide retailers with fresh merchandise. Resort pieces arrive at retail during the Christmas holidays and linger until the spring collections debut. This means that these pieces have a long time on the full-price selling floor, which is a relief for retailers that have to aggressively price apparel during the holiday season.