WASHINGTON — Marriott International wants to give its housekeepers a raise — and it is hoping customers will chip in.

Beginning this week, a number of the company's hotels will begin providing envelopes in guest rooms to encourage visitors to tip workers. The initiative, called "The Envelope Please," is a partnership with A Woman's Nation, a nonprofit organization founded by journalist and former California first lady Maria Shriver.

"In conversation with Maria, she said it had struck her that too often women are in positions that we forget to acknowledge," Arne Sorenson, chief executive and president of Bethesda, Md.-based Marriott, said in an interview.

"In a hotel, obviously we tip the bellman or wait staff. But often we don't see our housekeepers," he said. "We don't have that personal interaction, so we just don't think about it."

The American Hotel and Lodging Association, a trade association, suggests tipping housekeepers between $1 and $5 per night.

The association recommends leaving the money daily rather than at the end of a stay to ensure that the person cleaning the room each day is the beneficiary.

Housekeepers make up the largest group of employees within hotels managed by Marriott, comprising more than 20,000 positions in the United States and Canada alone. They are paid by the hour, and their schedules tend to vary throughout the year on the basis of hotel occupancy levels.

In 2012, maids and housekeepers earned a median salary of $19,780, or approximately $9.51 per hour, according to the U.S. Bureau of Labor Statistics.

"We think it's a great idea," John Boardman, executive secretary-treasurer of Unite Here Local 25, said about Marriott's tipping initiative. "It highlights the hard work that housekeepers do every day. We think it's a nice acknowledgment." The local represents workers at more than 30 Washington area hotels.

Even so, only a small fraction of the company's housekeepers belong to labor unions. Less than 10 percent of Marriott's workforce is unionized, according to Sorenson.

Marriott operates 18 brands, including its namesake line of hotels, as well as Ritz-Carlton, Gaylord and Renaissance hotels. The company announced last week that it plans to open 1,300 properties by 2017, taking its total number of hotels to more than 5,000.

Shriver said she got the idea for leaving envelopes in guest rooms after talking to housekeepers — and hotel guests — around the country. She approached Marriott executives with the concept about a year ago.

"I was talking to room attendants, who were overwhelmingly women, and they would tell me that people were pretty sophisticated about tipping the bellman or concierge, but they hadn't been educated that they could leave a tip for a room attendant," Shriver said in an interview. "There didn't seem to be a general awareness that you could, or should, tip a room attendant."

Recommended for you