Is 2-layer or 3-layer laminate better for a lightweight hiking jacket?

For a lightweight hiking jacket, 2-layer or 2.5-layer is usually the better choice; 3-layer is better when durability matters more than grams.

2-layer bonds a protective liner to the membrane — it is softer against skin and cheaper, but the hanging liner adds weight. 2.5-layer prints a protective dot-matrix coating instead of a full liner, cutting weight further, with slightly less durability. 3-layer sandwiches the membrane between face and backer and survives heavy pack-strap abrasion and repeated washing best. A simple rule: under ~150 GSM total weight, specify 2.5L; over it, 3L earns its cost.