I think the jury remains out on where siliconized fabric will find its place in the market. Introduced about three years ago by Nextec, this material consists of threads that are soaked in silicon before woven into fabric. The process can be used with many different types of thread, so can result in fairly heavyweight materials or very light ones. Siliconized fabrics of this sort are very water- and wind-resistant. Breathability, in my experience, is marginal. Personally, I think tents are a good use for the stuff. You can make a light single-wall tent with siliconized fabric that is as waterproof as you need it to be, yet breathes just well enough to keep condensation reasonable. And the cost is MUCH less than the Gore-Tex derivatives or other expensive fabrics now found in most single-walls. That’s what Six Moons Designs is doing in a tent like the Europa ($245), which sleeps two yet weighs only two pounds, four ounces.
Why isn’t the stuff showing up in products from Sierra Designs or other makers? As I said, the jury still is out on this kind of fabric. A small company like Six Moons can afford to take a chance on a new fabric in an effort to set itself apart. Sierra Designs or Mountain Hardwear have carefully built a reputation with somewhat conservative engineering, and are reluctant to mess with that. I’d have to try a tent made with siliconized fabric before rendering a final judgment, but overall I think giving one a shot is a reasonable risk.