IF YOU TRAVEL A LOT you get used to the drill. Hotels, motels, resorts, your favorite airline or cruise line may have snagged your business. But it is nearly impossible to find one that will leave you alone.

A hotel chain, for example, wants you to know that it is a lot like you. It may be a mass of buildings, elevator buttons and brass-plated trolleys for bags. But it is special. A brick-and-mortar being with a heart. Starwood Hotels have a personalized menu for pillow puffiness, after all. Even a Motel 6 has its particular brand of lotion and shampoo.

The bathroom is where your hotel’s earnest personality really begins to beam. Cheerful cardboard pop-ups bloom next to the sink (“Did You Forget Your Toothbrush?”), a truly clean toilet shows off its prestigious plastic strip, and a placard near the towels cordially invites you to step up and Save the Planet.

Save the Planet, did you say? This little billboard, on just about every bathroom bar these days, is my favorite hotel pleasantry.. All I have to do is “choose.” Asking for new towels means wasting detergent. Re-using my damp one saves it. I am honored to help. And, while the cards don’t say this, I am glad to do my part to cut the hotel’s operating costs, reduce its laundry-room workforce and improve shareholder value.

I use and re-use my smelly towels for days on end. But I’ve a confession. While the terrycloth stays on the rack, I snag the towel card itself and stick it in my suitcase. I’ve amassed a world-class collection of these things.

You might think that they’re all the same. Laminated lectures printed up in bulk. Then check out the samples below — actual text from cards currently hanging in hotels and cruise ships around the globe. I’ve grouped my favorites into seven basic types. But when it comes to the cards, themselves, each is special. Distinctive.

Just like hotel chains. And just like you.

1. Instructive towel cards

A good towel card doesn’t just ask questions. It offers a helpful little hygiene lesson or two. It’s there for you just in case you never learned how to wash up properly — or maybe you forgot. Here’s an example from a Norway-based cruise line:

“If you imagine the tons of towels which are washed each day you can picture the enormous quantities of detergent that is used. Thank you for helping. How to wash your hands: A) Wet hands with warm water. B) Apply a generous amount of soap. C) Rub hands together for 20 seconds. D) Rinse hands. E) Dry hands with towel.”

2. Chic towel cards

This type comes on good stock and in tasteful beiges and grays. Typefaces can be edgy and tough to read, and the card may be cut in a creative little hook so it can swing on its rack. Here’s one from a posh hotel in Dublin that included a blurb offering bathers a pricey “glass of champagne with strawberries & rose petals”:

“As part of our commitment to a clean environment, we offer you the choice of reusing your towels. If we can be of any further assistance, please contact our style department at Extension O.”

3. Bossy towel cards

Some towel cards refuse to focus on the question at hand. Since they’ve got your attention, heck, why not badger you about other ways to become a caring global citizen? From a die-cut, four-panel card displayed at a budget hotel chain:

“Here are some of our other suggestions that we all can do: Report noisy, leaky faucets and toilets. Fill sink basin to shave. And please take short showers.”

4. “Gee, that’s a relief" towel cards

This kind of towel card reassures us that, even for jerks who choose not to reuse their towels, basic services — such as, say, breathable air in your room — will probably still be provided.

From a mid-range business hotel chain:

“If you would prefer not to participate in this program, simply leave this card on your pillow and towels and linens will be changed. As always, linens and towels are automatically changed after every guest checkout.”

5. Euphemistic towel cards

This approach pops up in grand old hotels or at inns with a heavy dose of Victorian décor. Phrasing tarts up the issue to the point where the card may appear to have little or nothing to do with laundry. From a big downtown hotel in Melbourne, Australia:

“Welcome to the hotel’s green program. In the interests of conservation, you choose to retain any of the offered towelling by simply hanging the items following use. Thank you for your participation in initiatives that better service the environment.”

6. Paranoid towel cards

Along with the usual warnings about damage to the environment, this type raises new and sometimes extremely weird worries in the mind of a guest. From a card at a hotel on the Gaspé Peninsula, in Quebec:

“In order to keep our costs at a minimum, we exercise a firm control of our inventory. If you have any reason to believe that you don’t have the right number of towels, please advise us immediately.”

7. Ultra-minimalist towel cards

In today’s boutique hotel, a fingerprinted and creased towel card could easily spoil the effect of its cool, clean, chrome-and-halogen décor. So the notice shows up on a translucent overlay stuck to the wall. And it is as bare-bones minimal as its hotel. Just the basics, such as in this example from a cutting-edge four-star in Lisbon:

“Towels on the floor mean ‘change them.’ ”

This made perfect sense to me. No sanctimonious sermon. No endless speech. But even here, the urge to lecture guests was just too strong to resist. As I was about to head to bed, I spotted something tiny next to the sink. I got my glasses. I turned up the halogen light.

“Please,” urged a sheepish little sign. “Please don’t leave taps on unnecessarily.”

Peter Mandel, of Providence, an occasional contributor, is a travel journalist and writes adventure books for kids.