Confronting the worst job market in decades, many college graduates who expected to land paid jobs are turning to unpaid internships to try to get a foot in an employer’s door.

While unpaid postcollege internships have long existed in the film and nonprofit worlds, they have recently spread to fashion houses, book and magazine publishers, marketing companies, public relations firms, art galleries, talent agencies — even to some law firms.

Melissa Reyes, who graduated from Marist College with a degree in fashion merchandising last May, applied for a dozen jobs to no avail. She was thrilled, however, to land an internship with the Diane von Furstenberg fashion house in Manhattan. “They talked about what an excellent, educational internship program this would be,” she said.

But Ms. Reyes soon soured on the experience. She often worked 9 a.m. to 9 p.m., five days a week. “They had me running out to buy them lunch,” she said. “They had me cleaning out the closets, emptying out the past season’s items.” Asked about her complaints, the fashion firm said, “We are very proud of our internship program, and we take all concerns of this kind very seriously.”