The simplest and lightest method, common in mid-layers, but it can create "cold spots" at the seams.
Look for a high ratio of down clusters to feathers. A 90/10 ratio is considered premium and offers the best insulation and packability. 2. Check the Construction How the jacket is sewn determines how well it traps heat: how to buy a good down jacket
A "good" jacket should include functional details that enhance its performance: Down Clothing Buying Guide - Mountain Equipment The simplest and lightest method, common in mid-layers,
These are the stitched compartments that hold the down. The simplest and lightest method