Fleece, synthetic fill, and down: the big three insulators for outdoor garments since before I can remember. Synthetic’s have come on strong from the back of the pack in the last 15 years, down fill powers have crept higher, and fleece has undergone myriad transformations in an attempt to address the three reasons why so many people spend more money on the other two (lack of compressibility, wind resistance, and poor warmth to weight ratio). The stereotypes concerning the three have remained largely unchanged over recent decades. Down has the best warmth to weight ratio, but does poorly when exposed to moisture. Synthetic fills remain warm(er) when wet, are more compressible than fleece but less than down, and degrades over time. Fleece is cheap, durable, warmest when wet, but takes up a ton of space and is the least warm for the weight.
So how well does conventional wisdom stack up against empirical and experiential testing?
I’m beginning what will be a very extensive BackpackingLight investigation into this question, and some bathtub saturation testing recently produced some noteworthy results. Both graphs are drawn from the same data, and show three garments with comparable insulative values and feature sets. The key numbers in the below graph are the dry weights of each.
Drying conditions were controlled, and not favorable for quick moisture evaporation. There is a lot more to come with this project, but one of my initial hypotheses is that conventional wisdom may not be well based on people actually getting their insulation soaked in the backcountry.
Part 1 of my BPL sub-8 oz waterproof-breathable jacket state of the market report went up earlier this week, and the second part, containing the discussions of each of the ten jackets and anoraks, will go up next. In summary, I found that fabric quality seems to matter (in several respects) more than mere weight, and that the benefits of jackets heavier than 8 oz are for most users likely illusory. I also found that a disconcertingly large number of gear makers can’t get hood design right, which is as silly as it is discouraging.