You may also be surprised to learn that the amino acids in silk helps sooth you to sleep, giving you a rejuvenating rest that is so hard to get when traveling. Best of all, our sleep sacks are very light in weight and they pack into a very small space, making them the perfect travel companion inside your luggage. Machine wash gentle cycle and hang to dry. Silk dries very quickly, so you can also hand wash the sleep sack in your hotel room and hang it in the shower to dry during the day.