I love the tagline that Black Diamond has for this jacket – “There’s a fine line between splitter blue skies and afternoon thunderstorms in the mountains.” That is so true, and anyone who’s spent a season in the hills has a story of being caught out by unexpected inclement weather. That’s why it’s nice to have an ultralight, versatile shell like the Black Diamond FineLine.
Black Diamond FineLine Stretch Jacket Features:
- Built with BD.dry waterproof/breathable/windproof solution
- Stretch shell fabric increases durability and comfort
- Underarm gussets for added mobility
- Adjustable, climbing-helmet-compatible hood
- YKK Reverse coil PU coated center front zipper
- Stows into external chest pocket with carabiner clip loop
- Low-profile, elastic cuffs
- Fit: Slim
- Weight: 8.1oz
- MSRP: $129.99

Light, stretchy, and sleek:
The FineLine has been a fine companion throughout the spring and early summer here in the PNW. I enjoyed taking it on some springtime ski touring, a few scattered day hikes, and a Mt. Hood climb. The diversity of these adventures speaks to the versatility of the FineLine: it’s a very light jacket, but it can do a lot.
The key to having a happy experience with a light jacket like this is reasonable expectations. This is not the same as buying a heavy-duty Gore-Tex shell that can last for years. Those jackets are heavier, use different waterproofing techniques, and tend to cost a whole lot more. The FineLine is an ultralight, highly packable jacket that’s meant for lighter use in lighter conditions.
Here’s what I mean by that. The FineLine uses a very light fabric (my guess is 20D, though BD does not say) which is treated with a polyurethane coating. That is the ‘.5’ in the 2.5L BD.dry fabric. PU is one of the lightest treatments available and it promotes a jacket’s ability to be waterproof and also stretchy. However, the flip side is that it degrades more quickly than, say, a Gore membrane. You’ll first notice this in high-wear areas like the shoulders and inner elbows.

So, all that to say, if you want this jacket to have a long and happy life, you need to recognize that it’s good for occasional use but shouldn’t be a daily driver in inclement weather.
The good thing, though, is that these traits result in an exceptionally lightweight and packable waterproof jacket. I took it on my ski tours and Mt. Hood precisely because of these qualities – I wanted to stay fast and move light with a minimal pack weight. The jacket clocks in at a measly 8.1oz, making it one of the lightest fully waterproof, seam-taped jackets available. It also packs into its single pocket, the chest pocket, with a carabiner loop to dangle this bad boy off your harness.

The FineLine’s other fine quality is how well it wears and moves with you. It’s a wonderful shell to use, especially while alpine climbing. The long, thin fit fits well underneath a harness. The fabric has inherent 4-way stretch, so it feels like you can do anything while you’re wearing it.
The jacket has a small, carefully tailored set of features. There are no velcro cuffs, just a slim little reach of elastic. There’s just a single pocket on the chest, which can happily accommodate your large phone and a couple bars. There’s a single hem adjustment and a single hood adjustment. The hood is spacious enough to accommodate a climbing helmet and still preserve side-to-side range of motion.

The Good
- Very light, very packable
- Stretchy fabric moves with you, and the tailoring is excellent
- All features work as they should
- Fairly affordable by the standards of waterproof jackets
The Bad
- Won’t have as much longevity as more costly options
- Some might miss hand warmer pockets
The Bottom Line: Black Diamond FineLine Stretch
This is such a great jacket for those who are looking for something light and packable. It doesn’t have the durability to be a daily driver in harsh conditions, but for that lightweight summer shell it’s hard to beat. The fit is excellent and the range of motion stands out.
Buy now: Available from Backcountry.com