Mummy bags win hands down as the most thermally efficient bag design. An ultralight down mummy combined with an ultralight down jacket and pants creates a remarkably warm and versatile sleeping system for colder conditions. Join Will as he rounds up and rates the lightest three-season down mummy bags.

An ultralight sleeping system is a core component of an ultralight backpacking gear kit, and it requires careful planning so the components are coordinated with each other and appropriate for the expected conditions. This article is the first of three coordinated articles covering the insulated components of an ultralight three-season sleeping system capable of handling colder temperatures. Such a system - consisting of an ultralight down mummy-style sleeping bag, down jacket, and down pants - minimizes weight while providing maximum warmth and versatility without compromising safety or comfort.

Part 1: Ultralight Down Mummy Sleeping Bag

Part 2: Ultralight Down Jacket (not yet published)

Part 3: Ultralight Down Pants (not yet published)

ARTICLE OUTLINE

• Introduction
• The Conditions
• In Defense of the Mummy Bag
• The Mummy Bag Based Sleeping System
• Not All Three-Season Down Mummy Bags are Created Equal
• Is the Evolution of the Mummy Bag Dead?
• Selection Criteria
• The Bags
• Evaluation Criteria
• Sleeping Bag Ratings
• Standouts Based on Functional Design and Features
• Standouts Based on Specific Situations and Needs
  • Lightest Bags
  • Warmest Bags
  • Lightest Warmest Bags
  • Best Bags for Short People
  • Best Bags for Slender People
  • Best Bags for Big People
  • Lightest Bags with a Long Zipper
  • Best Bag for Hammock Users
  • Best Value
• Individual Bag Summary
• Future Mummies

# WORDS: 8670
# PHOTOS: 20

We cover yet another Primus heat-exchanger stove system in this Review: the Primus Eta PackLite. This is basically modelled on the Eta Power system, but smaller and lighter.

The Primus Eta PackLite could be called the Primus Eta Power on weight-reduction. The Eta PackLite stove is only moderately similar to the Eta Power, and in a distant sort of way, and the pot is different too, but the concept is very similar. The burner is a highly modified Primus Micron Ti 2.5 (or Primus Express). The main air-mixing burner tube is horizontal, and a pre-heat tube has been added. The burner assembly can be completely removed from the base if you want: it is held in place with a standard clip-pin and a Terry clip. The pot supports can be rotated inwards to reduce the size for packing.

ARTICLE OUTLINE

• Master Index
• Introduction
• Stove Performance
• Primus Eta PackLite

# WORDS: 1350
# PHOTOS: 5

This jacket really rocks - an excellent balance of light weight, basic features, warmth, wind and water resistance, and cost.

Eddie Bauer was not on my radar screen to find lightweight performance outdoor clothing. That changed with the introduction of their First Ascent line, in concert with a successful Everest expedition in May 2009. Their experienced climbing team provided a lot of input into the garments' design, which is evident in the Downlight Sweater. This jacket has an excellent balance of light weight and essential features, it's very warm, and it's a great value.

ARTICLE OUTLINE

• Introduction
• Description
• Performance
• Comparisons
• Assessment
• Specifications and Features

# WORDS: 1620
# PHOTOS: 8

Silnylon and spinnaker fabric have long been mainstays in making ultralight gear, but they require careful construction to avoid failures at seams or damage from abrasion. Laminating the fabric offers a solution to those problems.

I have a talent for mistaken first impressions, and questioning those first impressions is the single most useful thing I've learned on the journey to lighter backpacking. I use the following standard two-word response to those times my own (not so) good sense tells me that a technique can't work for me: Prove it! Tarps, quilts, frameless packs, low-cut lightweight footwear and leaving most spare clothing at home were all initially rejected out of hand, but are now mainstays of my gear list and planning. This article is the outcome of questioning another of those faulty first impressions.

Several years ago, someone in a forum somewhere asked about attaching guyline loops to the center of large panels on silnylon shelters. One answer was Sew the loop to a scrap of silnylon and glue that assembly to the panel using GE Silicone II. My reaction? Nah, that can't be strong enough. When I decided to add additional guyout loops to a shelter, it was time to prove it.

I completed that shelter modification just in time to test it in a storm that delivered six inches of wet snow. The glue held under a load that exceeded the holding power of Kelty TripTease line threaded through ITW Nexus LineLoc 3 adjusters, which are widely used on shelters found in the gear lists of many BPL members.

Since that time, I've used the same procedure to attach guyouts to two other shelters, to attach reinforcing patches for guyout loops at the edge of tarps, to attach stake loops to a bivy floor (avoiding ground level stitching), to make two-layer laminates for use where a stronger, stiffer, or more abrasion resistant material is wanted, and I'm currently trying it in seam allowances and high stress areas in a pack I'm making. Recent discussions on Backpacking Light's forums have revealed other members enjoying success with glue laminated guyout reinforcement patches.

ARTICLE OUTLINE

• Introduction
• Tools and Materials
• Laminating Procedure
• Examples of Use in Gear Construction
• Tarp Guyouts
• Heavy Duty Silnylon
• Reinforcing Seam Allowances
• Summary

# WORDS: 1790
# PHOTOS: 20

Remarkably lofty and warm for a 30 F (-1 C) rated bag – this is the first sleeping bag I have tested that’s warmer than its claimed temperature rating!

My preference for an ultralight sleeping system that will handle occasional unexpectedly cold nights is a 30 F rated mummy-style down sleeping bag with enough girth so I can wear extra clothing inside to extend its warmth when needed. Backpacking Light will publish a series of three articles in spring 2010 covering the insulated components of an ultralight three-season sleeping system for colder temperatures. This review is a separate evaluation of the Sierra Designs Nitro 30 sleeping bag.

When selecting sleeping bags to include in my upcoming state of the market article on ultralight three-season down mummy-style sleeping bags, I at first rejected the Sierra Designs Nitro 30 because it weighs 26 ounces. The lightest bags in this category weigh in at 19 to 23 ounces. Then I noticed that the Nitro 30 (size Regular) contains 12 ounces of down, while the lighter bags contain 10 ounces of similar quality down. That's 20% more, which should translate to more loft and more warmth. The Nitro 30 has some other features that also should contribute to warmth, so how does the slightly heavier Nitro 30 stack up compared to the lightest 30 F (-1 C) rated sleeping bags?

ARTICLE OUTLINE

• Introduction
• Description
• Performance
• Comparisons
• Assessment
• Specifications and Features

# WORDS: 2080
# PHOTOS: 9