In reply to Jon Wickham: Actually, as I said - have had a momtentum jacket for a couple of years now, used it for climbing, summer and winter, dog walking, bumming around in the pub etc, and it's held up very well considering how light the fabric is. The Demand is made from exactly the same fabric. I know this for definite as I know the southern rep and he told me this. So I shouldn't be too concerned about the fabric. The weight comes from lack of features, elastic cuffs, a one sided hem drawstring etc. rather than a particularly light fabric... it's much heavier fabric than used in the kinetic products rab do...