Black Diamond Fineline Stretch Shell Review

We pushed the Black Diamond Fineline Stretch Shell through adventures of all shapes and sizes, deliberately choosing stormy days to go out and push its limits. From all-day alpine climbs to casual afternoon hikes, we explored every aspect of the Fineline. One tester summarized his findings, “The Fineline strikes the ideal balance of weight to performance that will appeal to many outdoors enthusiasts. It gave me just enough protection to serve on longer trips, if heavy rains were not in the forecast, yet it didn't slow me down when I tossed it in my pack.”

Performance Comparison

Water Resistance

The Fineline Stretch Shell delivered reasonably well on its primary job: repelling water. We tested this metric by logging weeks in the field with every layer in the review lineup, taking detailed notes to allow for direct comparative analysis. By hopping in the shower with each jacket, we were able to dive in and more objectively size up the Fineline against others in the lineup. It came in towards the front of the pack, particularly among those options offering excellent mobility.

The Fineline Stretch Shell, made with BD.dry 2.5L fabric, offers decent weather protection, although we still think it's best suited for rain storms that are on the friendlier side. When faced with all day drizzles or shorter downpours, this jacket kept us dry, but during prolonged deluges, it wasn't quite up to the job and we got slightly wet. Throughout our shower testing, our findings were similar with large, 25 square inch wet spots appearing on our underlayers due to water soaking through the Fineline's material. For shoppers needing a rain jacket for the occasional storm in normally drier climates, this option will likely work well, and is substantially lighter than much of the competition. If you need a jacket that can handle hours of intense rain, like in the Pacific Northwest, we recommend looking at another option.

Breathability

This metric is important to anyone planning to get active in their rain gear. The Fineline Stretch Shell did well here, and this score became 20% of the final score. We tested this metric by first spending weeks with each garment in the field for some real-world analysis. Then, we conducted a standardized uphill test, sizing up the sweat spots that appeared on our underlayers afterwards to better understand how well this jacket can pull heat and moisture out to cool and dry the body.

The Fineline Stretch Shell is made with a 2.5 layer construction, utilizing a liner for the next-to-body layer. This type of rain jacket construction can vary greatly when it comes to the degree of breathability it produces. Fortunately, Black Diamond's in-house fabric, BD.dry, boasts improved airflow by incorporating a substantially less “rubbery” liner than the competition. This doesn't entirely eliminate that “clammy” feeling one many experience with sustained uphill adventures — our testers did notice moist skin on humid or warmer days — but when traveling at a more moderate pace or on cooler days, our testers found such sweaty skin proved minimal.

Comfort and Mobility

We spent several days in each jacket to test this metric while participating in various outdoor activities. We took it fishing, went climbing, and spent mornings hiking, all to assess better how well it accommodated the movements required for each. We also carried out our “lab” test, which includes a set of standardized moves conducted in each jacket. The Fineline Stretch Shell delivered excellent results, with little restriction to our movements or lift in our midsections.

It's rare to see a rain jacket with two-way stretch fabric, but the Fineline Stretch Shell offers just that. While it isn't as stretchy as a fleece or a softshell, this model boasts excellent movement. We found the cut to strike a rare balance of slim fit for technical use and loose enough to offer decent mobility. The sizing can be a bit tricky, but for those who find the Fineline a bit snug, one can simply bump up to the next size. The adjustable hem and cuffs further allow one to dial in the fit until its just right.

For shoppers needing a more technical layer in this jacket category, we also appreciated the helmet compatible hood, which is less common in the rain jacket world. The entire jacket fits into the right hand pocket, with a carabiner loop allowing you to leave this jacket clipped to your harness.

Weight

The weight of the Fineline Stretch Shell became just 10% of its score, even if it is an important metric for some shoppers. To get there, we simply weighed each jacket and then applied a standardized weight ratings calculator to produce a number between 1-10. This jacket came in towards the very top of the lineup. Our lead reviewer, Zach Lovell, shared, “This is where I saw the Fineline really stick out; while it isn't the absolute lightest option, it's among the lightest jackets that are fully featured.”

While some featherweight rain jackets are out there, most offer minimal weather protection and limited features. The Fineline Stretch Shell boasts an excellent weight of 9.40 ounces and offers a full list of useful features plus a 2.5-layer fabric construction. It's also highly packable, making it one of the better options for weight-conscious shoppers still needing a high-performing shell.

Construction Quality

Durability is something all shoppers think about. While it's not of top importance when selecting a rain jacket, the quality of construction still receives 10% of the total score. Throughout field testing, we kept detailed notes on the Fineline Stretch Shell's performance in this regard. We also conducted extensive research on the materials used in construction and investigated any user complaints related to longevity or defects experienced over time. The Fineline was reasonably sturdy compared to many other options we tested.

As mentioned in other metrics, the Fineline Stretch Shell utilizes two-way stretch nylon and an interior liner. Typically, stretchier materials tend to be more abrasion resistant. While we found this to be the case in our field testing with the Fineline, we noted some users report the face fabric rips more easily than perhaps others might. Other Fineline users also reported that the liner began flaking after a year or two in action. Although we didn't have either experience throughout our testing period, we did evaluate both concerns directly, further investigating such potential defects in construction by deliberately scraping the Fineline's exterior and liner across abrasive surfaces to see if tears would appear. We are pleased to report the jacket held up quite well, though we cannot say if the same issues might not eventually appear a year or two down the line.

Should You Buy the Black Diamond Fineline Stretch Shell?

This jacket is worthy of a closer look if weight is a top priority and you need a true rain jacket with multi-layered construction rather than a light shell for the occasional thundershower. This is also one of the more cost-friendly garments among the higher scoring jackets in our lineup, making it a great option for active users.

What Other Rain Jackets Should You Consider?