Design Salt MummyLiner

Since being introduced to Design Salt's silk MummyLiner almost two years ago, I haven't spent a single night in the outdoors without my silk liner. Rain or shine, cold or warm, it doesn't matter. If I'm sleeping in the outdoors, I'm sleeping in my Design Salt silk MummyLiner. It is one of my favorite products.

The Design Salt MummyLiner is a tapered lining for your sleeping bag which comes in a variety of fabrics. I've tested both silk and flannel. A liner adds warmth and extends the life of your sleeping bag by reducing the need to wash your bag. By sleeping in the liner, the dirt, sweat, and oils form your skin and undergarments remain in the liner, rather than the sleeping bag. The fewer times you need to wash your bag, the longer it'll do its job effectively.

Two key features across Design Salt's products are minimum weight and packing size. For example, their top of the line silk MummyLiner weighs 4.7 ounces and packs into a five-inch-square bag. The silk liner adds 9.5 degrees F of warmth to your sleeping bag. Silk is the best fiber for optimizing warmth, while reducing weight and size. It also dries very quickly when wet, and breathes well. This is key as your body gives of a good deal of moisture while you sleep.

The cotton flannel mummy liner, weighing 16.0 ounces, is much heavier and larger (more than twice the size), but adds 12.3 degrees of warmth.

MummyLiners may serve as your primary sleeping bag in warm weather climates. I take the liner out and sleep inside the liner on top of my sleeping bag on warmer nights. The bag gives extra padding beneath me for comfort. If the temperature drops enough during the night to give me a chill, I just crawl with the liner into my sleeping bag. I can leave the zipper on the bag open for ventilation or zip it up for the full warming effect.

In winter, the silk liner is like instant, liquid warmth. Occasionally, I've awaken on very cold nights to find an arm outside my bag, or exposed to the cold. Just pulling the silk liner up over the arm brings instant warmth, like you've just put your arm into a warm shower. That extra 9.5 degrees gives comforting reassurance when your thermometer shows the temperature dropping rapidly on winter outings.

Design Salt's silk liners aren't cheap. Silk has always been an expensive fiber. A silk mummy liner will run you a cool $70 retail ($66 for the natural color). But, compared to the cost of your sleeping bag, that may be a bargain. For the comfort, light weight, small size, extra warmth, and protection that liner affords the bag by keeping the dirt from your body away from the sleeping bag, the silk liner is worth the price.

Flannel runs only $30-$34 (depending on color). Personally, I'm not sure I'd carry the flannel liner on most of my backpacking trips due to its size and weight, but I'm not a flannel lover either. One of the other testers has frequently carried the flannel into the field, especially on winter trips. For car camping, the flannel would be a great addition to your nighttime gear.

Other fabric choices are micro-fleece, cotton, and a silk/cotton blend. I'd stay away from the cotton and cotton blend for high activity outdoor recreation, as cotton tends to trap moisture. For backpacking, the silk and flannel are the best choices. Design Salt recommends the fleece for high humidity activities, such as sailing or kayaking.

Design Salt also makes rectangular liners, or TravelSheets, for bedding during adventure travel trips, but that's another review. . .

Steve Mann is the Editorial Director and a Co-Founder at GearReview.com.

For more information, contact:
Design Salt
PO Box 1220
Redway, CA 95560
800-254-7258