NEW YORK — Do you leave a tip in your hotel room for the maid? Marriott is launching a program with Maria Shriver to put envelopes in hotel rooms to encourage tipping.

The campaign, called “The Envelope Please,” begins this week. Envelopes will be placed in 160,000 rooms in the U.S. and Canada. Some 750 to 1,000 hotels will participate from Marriott brands like Courtyard, Residence Inn, J.W. Marriott, Ritz-Carlton and Renaissance. The name of the maid will be written on the envelope along with a message: “Our caring room attendants enjoyed making your stay warm and comfortable. Please feel free to leave a gratuity to express your appreciation for their efforts.”

Shriver, who founded an organization called A Woman’s Nation that aims to empower women, said many travelers don’t realize tipping hotel room attendants is customary.

So how much should you leave? Marriott International CEO Arne Sorenson says $1 to $5 per night, depending on room rate, with more for a high-priced suite. Michael Lynn, a professor at Cornell University’s School of Hotel Administration, says his research shows that “30 percent of people stiff the maid,” while 70 percent said they usually leave a tip.

Sorenson noted that housekeepers “are less frequently tipped” than other hotel workers because they do an “invisible task.”