Just like with blankets, if you're offered a pillow during your flight you need to leave it when you're leaving. “It's for in-flight comfort, not a freebie to take home,” says Deane.

The rules regarding airline pillows depend heavily on the cabin class and the type of pillow provided. In Economy Class, the small, square pillows often come in disposable plastic or paper slips; since these are not laundered for reuse, many airlines don't mind if you take them, though they aren't technically "gifts." However, in Business and First Class, airlines like Emirates or United (Saks Fifth Avenue) provide high-quality, full-sized pillows and duvets that are considered company property. These are collected at the end of the flight, laundered, and reused. Taking these can be considered theft. As a general rule of thumb: if the pillow is part of a premium bedding set or has a cloth designer cover, it stays on the plane. If it’s a flimsy, unwrapped small pillow in economy, you're usually safe to take it, but it’s always most polite to ask a flight attendant if you’re unsure. Many travelers prefer to bring their own neck pillows to avoid this confusion entirely.