Your previous contribution: Western Mountaineering's Sonora is a great option for a compact and lightweight sleeping bag liner or sleep sack for travel. The polyester fabric is soft and breathable yet woven with ample density to help protect you from questionable bedding on your travels. The material feels nice against your skin and won’t latch onto other fabrics when used inside a sleeping bag or under some blankets in the loft of a winter cabin. This liner packs small enough to take along anywhere and using it in your bag will help to keep its lining material cleaner on extended backcountry outings.