A midlayer might be the most versatile and well-used piece in your layering kit. From hiking to skiing to climbing, these jackets, vests, and hoodies play an integral role in keeping you warm.

So, what constitutes a midlayer? They’re layers that help your body retain the heat it creates, basically providing insulation from the inside out. Layers in this category, whether wool, fleece, synthetic, or down, efficiently trap heat and keep you warm.

CHOOSING THE RIGHT MATERIAL FOR YOUR PURSUIT

A jacket’s material influences how efficient and breathable your midlayer will be. Depending on your chosen activity and location, a certain material will be a better pick over another. Fleece midlayers are soft, lightweight, and very breathable; this makes them great for higher-output activities or milder temps, but since they are so breathable, you’ll need a shell to block wind.

Synthetic midlayers are packable and perform better than down in wet conditions. Down is a tried-and-true staple when it comes to insulation, providing both protection from the elements and compressible warmth. We’ll break down the different styles of insulating midlayers below and explain the best scenarios for each family of jackets and hoodies. Whether it’s cold weather cragging, moving through the mountains, or hitting the skintrack, our midlayer families provide the warmth and insulation you need for your next outing.

SYNTHETIC AND DOWN INSULATING MIDLAYERS

SOLUTION

The Solution insulation spans a wide range of insulating needs. For midlayers, the Solution 1.0 and the Solution 2.0 are synthetic layers designed to shut down the cold from the inside out, making them versatile cold-weather picks. The 1.0 has breathable side panels, which makes it a bit better as an active layer, while the 2.0 provides full insulation and works great as a staple for any cold-weather activities (think: throwing on at the crag in between burns). Both jackets are packable, making them great on-route layers for climbing.

ACCESS DOWN

The jackets found in this family are down alternatives to the Solution. They’ll provide a cozy insulating layer in cold conditions, whether you’re skiing, climbing, or wearing around town. The Access 2.0 is great for layering under a shell on cold ski tours, or wearing alone to work, the gym, or at camp. It has a buttery soft outer material that makes it comfortable and wearable, but not necessarily very useful in any kind of weather, since it’s not water-resistant.

FIRST LIGHT

The First Light series contains some of our most iconic midlayers. These jackets have been staples on cold weather missions where your are moving through the mountains around the world for decades. PrimaLoft® Gold Active insulation provides breathable, stretchy warmth on the go, more so than, say, the Solution. This is the jacket that you’ll put on when you leave the house and keep on all day long. Its breathability is top-notch, and your body can regulate temperature through a full day of aerobic activity in the mountains.

FLEECE JACKETS

Here you’ll find the traditional jackets and hoodies that come to mind when you think: midlayer. Fleece midlayers offer comfort and breathability. They feel like technical sweaters that you won’t want to take off. The Diverge Half Zip offers warmth in a sleek, technical design, making it great for climbing in cold weather. The Coefficient Storm Hoody is slightly more durable and offers better weather protection, thanks to its wind- and water-resistant DWR coating. It’s great for high-exertion cold-weather activities in stormy weather. The final fleece in this category is the Rift, which is soft but lacks weather resistance. Wind will cut through this cozy layer, but it’s a classic for camping trips and around-town use.

CONCLUSION

If you are doing things outside, whether skiing, running, hiking, or climbing, you’re going to need a midlayer. Jackets that can provide warmth and insulation while remaining packable and lightweight are a must when you’re out and about. Each category above includes jackets that work well in specific situations, and hopefully now you have a better idea of the right jacket for your next mountain pursuit.

Dive deeper in our cold-weather apparel. Learn more about Black Diamond Fleece, and How to Choose an Insulated Jacket.

KEY TAKEAWAYS

Midlayers insulate by trapping the heat your body produces: From wool, fleece, synthetic, and down, they're the versatile layer across hiking, skiing, and climbing.

Material determines performance: Fleece is soft and highly breathable but needs a shell for wind; synthetic is packable and handles wet conditions; and down is a classic option that offers compressible warmth.

Synthetic and down options cover different cold-weather needs: The Solution 1.0 is the more active pick thanks to its breathable side panels, while the Solution 2.0 offers full insulation for staying warm between climbing burns. The Access 2.0 down layer is comfortable for ski tours or everyday wear but isn't water-resistant.

First Light is the highly breathable choice; Fleece is the everyday option: Its PrimaLoft Gold Active insulation is stretchy and breathable, letting you regulate temperature through a full day in the mountains. Fleece layers range from cozy to sleek and technical; just keep in mind they lack wind and weather protection.

ABOUT THE AUTHOR

Jane Jackson is a writer and editor based in the Sierra Nevada. She loves granite and being in the mountains, and has spent most of her adult life obsessed with rock climbing in all of its forms.