Fabric Warmth Ratings

Layer Warmth Weight Stretch Type Best For Not Ideal For
Single Layer Light Lightweight Mechanical Stretch Cool conditions, mild activity, standalone or layered Very cold or stationary conditions
Active Stretch Medium Midweight Four-way / High-mobility High-movement cold-weather activity, skiing, snowboarding, outdoor work Low-output stationary use or extreme cold where warmth is top priority
Double Layer Medium Midweight Dual-layer Sustained cold, moderate activity, layering under outerwear High-output activity, mild conditions, lightweight-only preference
Micro Fleece Medium-High Midweight-Heavy Four-way / Flexible Moderate to high-output activity, layering under shells Very cold, low-output conditions needing maximum insulation
Mountain Fleece Maximum Heavyweight Mechanical Stretch Very cold conditions, low-to-moderate activity, all-day warmth High-output or dynamic activity requiring maximum breathability