(Wall Street Journal) — From her Gorgeous Look embroidery shop, Monica Adeola has a front-row seat on a new Nigerian consumer ready to dress up. Her customers—stay-at-home moms, young professionals and laborers with newfound spending money—barter over the latest embroidered dresses, blouses and shirts, which are known here as “lace.” No longer reserved for the rich, lace today is on the backs of motorcycle-taxi passengers and nightclub goers, part of Africa’s growing middle class. The African Development Bank estimates that the continent has around 300 million people with incomes in excess of their basic needs, up more than 60% from a decade ago. “We’re trying to rebrand lace,” says Folake Folarin-Coker, a Nigerian fashion designer who helped stage a lace-themed fashion show here last month. “There is a huge middle-income market in Nigeria.” The Nigerian lace industry also opens a window on broader change in Africa as a whole: As the consumer class expands, so, too, has the underground, informal economy.