
Built to move
Lightweight Insulation
Meant to stay on.
These are your go-to layers for high-output days in cold conditions — breathable, lightly insulated, and cut to move with you. Think grid fleece, air-permeable synthetics, and weather-shedding soft shells that shine when you’re grinding uphill but still need some warmth. Whether you're skinning, bootpacking, or just staying ready for that next break in the weather, these layers are designed to work hard and wear all day.
Field Tested · Guide Endorsed
Guide Picks
Skip the browsing — pick from the cream of the crop. Like our tagline says, we simplify outfitting.
2 colors available
4 colors available
Filters
11 products
Your Buying Guide For
Lightweight Insulation
Your lightweight insulation layer is all about balance — keeping you warm enough at rest, but not overheating when you’re on the move. Here’s how to pick the right one for your climate, output, and layering system.
Still have questions? Feel free to reach out!
What’s the purpose of a lightweight insulation layer?
It’s designed to trap just enough heat during moderate activity or mild conditions. Think of it as your go-to midlayer for days when a heavy puffy is too much, but a baselayer alone isn’t enough.
Synthetic or fleece — which is better?
Synthetic active insulation, like Octa or Coreloft, mimics fleece warmth but packs smaller and handles light moisture better. Fleece, especially grid fleece, breathes exceptionally well and feels great against the skin. For high-output climbs, many guides prefer grid fleece for its simplicity and temperature control.
What’s special about grid fleece?
Grid fleece uses a pattern of raised channels that trap warmth while allowing air to circulate. It’s lighter, more breathable, and faster-drying than traditional fleece — perfect for layering under a shell or wearing solo on dry, cool days.






























