Sierra Designs Isotope

[Ryan Jordan]

Waterproof is a stretch, you can read about that in our review here.

In that review, Alan writes:

“At 3,000 g/m2/day the Nanolite fabric is in the lower-to-middle of the pack for breathability. It is not as breathable as fabrics like Gore-Tex XCR or eVENT. Without any venting options other than a full length zipper this might not be the jacket for sustained uphill hiking in the rain.”

I’m not one for a lot of superlatives, but after spending three days with this jacket on a winter trek in Yellowstone, I’ve pretty much come to hate it. Ignore the numbers. Don’t even think this fabric approaches the breathability of newer Gore-Tex fabrics, eVENT, or even 2/2.5-layer proprietary fabrics from Marmot, GoLite, or Patagonia.

This fabric may well be a vapor barrier fabric. I would give it a “4” as a VB.

The redeeming feature of the jacket is that it’s light and seam sealed, which means it might make a nice shower shell for summer hiking. But the waterproofness as reported doesn’t have me terribly hopeful even for that.

So, you have a windbreaker that is among the least breathable waterproof fabrics known to man and is not exactly waterproof.

I do love the sky blue color.

[Author]

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