Stretch Construction, Fabric, Features

First and foremost, the REI Flash Stretch Rain Jacket is, well, a stretchy rain jacket. But to level set, we’re not talking yoga pants-levels of stretch here. On the spectrum of how stretchy a garment can be, it’s on the low end overall. But actually surprisingly high as rain jackets go! I perceive it to be slightly stretchier than the Black Diamond Stormline Stretch or Mountain Hardwear Stretch Ozonic, for example. Playing with the fabric, it stretches better on the bias (diagonal) than it does on the warp and weft (vertical and horizontal).

Two types of fabrics are used in manufacturing this jacket. There is polyester dobby weave featured in the upper torso, and polyester + 10% spandex blend featured in the lower torso and lower arms. REI doesn’t say, and we aren’t certain as to the strategy behind why either fabric is placed where it is. A quick hand feel implies that they are roughly equally as stretchy and equally as durable.

But we operate under the assumption that the stretchier of the two must be the dobby weave torso (since upper back is the most important stretch region), and the more durable of the two is the poly/spandex blend since it’s placed in high abrasion zones like the elbow and hip belt region. But odd, because it’s also the one with ADDED Spandex. A bit of a head scratcher, really. But performance differences between the two fabrics are basically imperceptible, so what does it matter anyway?

The end result for users is that it is more comfortable than a static fabric rain jacket, and allows an improved range of motion. However, reaching your arms above your head still pulls the hem upwards. Reaching an arm across your torso and you can feel the shoulder stretch and resist you, but still achieve a full range of motion while stretching your triceps.

The downside to stretch rainwear – not specific to this jacket but speaking generally – is that it’s less durable, heavier, absorbs more water, and the laminate has a shorter lifespan. Addressing durability first, we know that stretchy fabrics are more prone to snagging. It also does not have a ripstop grid. Regarding its heaviness, well, look at the numbers – most lightweight jackets come in 8-12 oz, and again, this is 17 oz in a men’s medium. Spandex, despite all of the stretch benefits, is also heavier than pure nylon/poly, and absorbs more water. Lastly, repeated stretches will overtime, cause damage to the laminate and how it’s bonded to the face fabric.

REI Co-op Flash Stretch Rain Jacket is not lacking for features. First and foremost, it has the single most important feature of all in full size pit zips. We also appreciate the hip-belt compatible hand pockets, which aren’t covered up when you wear it with a pack. Closing out the feature set, we note hook-and-loop wrist closure, cinchable hem closure, a massive front stormflap, nice zipper teeth, vertical and horizontal hood adjusters. The only feature it’s missing is a chest pocket, though that space is used by the aforementioned elevated hand pockets.