A high-quality sleep sack is a traveler’s best friend whenever you find yourself in less-than-ideal sleeping accommodations, or are crashing somewhere that doesn’t provide bedding, like a hostel, yurt, or backcountry hut. I thought I could get by without one—using my heavy backpacking mummy bag whenever the situation called for personal bedding—but after trying out Grand Trunk’s Bamboo Sleep Sack, I won’t be going back.

First off, this sleep sack is so soft, I don’t think I can ever go back to cotton. It’s lightweight, so it works beautifully in warm climates, but can be paired with a sleeping bag or blanket in colder weather. It’s roomier than my mummy bag, and features a nice slit down one side that can be tied back up for easy entry and more space. Best of all, it has a pillow pocket, so you can insert a pillow, which won’t slip around and disappear during the night.

I took the sleep sack along on our Mt. Hood, Oregon wilderness snowshoe overnight, in which the rustic hut we were trekking to came included with communal sleeping bags. I’d need the warmth of the bag, but didn’t relish the idea of sleeping directly where a stranger had the night before, so I wiggled into my sleep sack, then slid into the bag. The arrangement worked perfectly, and since the bamboo sleep sack is only 16 ounces, I avoided carrying in a heavy bag.

I also brought it along when I rented a room for the night through a vacation home site in Portland, OR, since I didn’t know ahead of time whether the rental included linens. Turns out, it did, but I was still glad to have my personal set in the form of the sleep sack. You can use the sack in tandem with a made-up bed, or shimmy into it under the sheets, to give you a nice barrier between hotel or rental sheets and your body. My only complaint is that the sleep sack tangled up and twisted a bit more during the course of the night than I’d experience in my mummy bag, presumably because it’s roomier and of lighter material.

The bamboo viscose material is soft, stretchy, and washes easily in a regular washing cycle. The feel reminds me a little of ‘t-shirt material’ sheets, but better. Plus, since it’s bamboo, it naturally wicks moisture away from your body. And of course, bamboo is a sustainable, renewable fiber, so you’re doing the planet a favor, too. Nothing synthetic here!

The bamboo sleep sack rolls into its own small cinch sack, retails on the Grand Trunk site, a new favorite in my short list of green travel companies, for $69. It’s even less on Amazon. While you’re checking out the sleep sack, take a look at their hammocks, shelters, tents, and hammock compatible sleeping bags!