I'm looking at a jacket from Outdoor Research which gives the amount of insulation used in just grams, which is nice an straightforward. On the other hand Arcteryx is confusing and uses g/m^2. Am I right in thinking the Arcteryx gives for it's jackets are only useful for comparing within their range, and that to compare to anything else I have to get one of their jackets and measure the surface area. Or is there some other available conversion I'm not aware of?

Having looked at them and various other sites, I'm pretty sure that when a manufacturer states its insulation as, for example, 60 g or 1.8 oz or whatever, they mean per square meter or square yard. Not all of them explicitly state it, but insulation for these kinds of items is almost always specified in units of mass/area or weight/area.

Hi Danny, a single type of insulation (Primaloft, Coreloft, etc) is used in a jacket, each with a particular density (by volume). So if Outdoor Research, Patagonia, etc give 133g in the body, 100g in the sleeve, 60g in the hood, that would mean drastically different thickness various parts. Is that correct though? Hoods seem like they're particularly thick.

which jackets?