A few years ago, plus-size lingerie was almost a taboo subject. Curvy or big women (no, that’s not a bad word) struggled to find styles that were pretty, comfortable, and suited their curves.

The OneStopPlus Group this week launched Fullbeauty.com, the online retailer’s first site dedicated to plus-size bras and lingerie. More than 600 intimate apparel items from 30 proprietary and ...