Powerstretch vs. R1: the same or different?

From my experience R1 (Polartec Power Dry) is much more breathable and a bit lighter than Powerstretch but not quite as warm. Both have a wicking finish, so it works well as a baselayer for cold temps or a midlayer.

The R1 will be more breathable and will dry quicker due simply to the "waffled" pattern woven into the fabric. I'm not sure about the differences between power stretch and power dry, but power stretch is usually woven into heavier fabrics. To me, my Mountain Hardwear power stretch shirt feels warmer than my Patagonia R1 hoodie, however the R1 hoodie has a much much superior fit to the MH. The superior fit of the R1 allows the fabric to be held closer to my skin for more thermal efficiency and comfort, which counts for a lot. I think Mountain Hardwear shirts are designed to fit on short, wide people who don't mind having a reversible zipper pressing into their adams apple. I have seen Cloudveil Run Dont Walk shirts in stores and they seem to use a slightly thinner version of power stretch than Mountain Hardwear, though I haven't tried any of them on so I can't comment on their fit.

R1 is really Powerdry by Malden Mills (or used to be, anyway). Malden’s Powerstretch is very similar, but has a higher lycra content to provide stretch. Both Powerdry and Powerstretch are available in several weights and finishes.

The Lycra in Powerstretch is fairly moisture absorbent. So, when saturated, Powerstretch takes longer to dry than comparable weight Powerdry. However, with small amounts of moisture, the absorbency of Powerstretch can provide a moisture buffering effect similar to wool, reducing “flash off” chilling from evaporative cooling.

FWIW, my favorite cold weather piece is the Mountain Hardwear Powerstretch Zip-T.

Cheers,

-Mike