Thin but they do their job when you remember that these are "light...". The fabric is thin and therefore not particularly long-lasting if the use is active.
I have a bad experience with these myself. They frayed from the surface and became holey after only a couple of uses.
Comfortable and warm
Tighter than thicker warmwool long shorts
Really great shorts. Snug fit.
Also good for exercise.
They work well as a 0-layer, i.e. under the 1st layer as underwear. Thigh length doubles the power.
I'm happy to buy it, it's easy to use, I recommend it
Warm, well-fitting and comfortable boxers.