Oh, right, it's glamored armor, so it isn't really cloth armor, it just looks like it. It's really a suit of something like +2 Full Plate, or more likely +5 Breastplate. Although then the language about "mithril cotton" and "adamantine threading" is confusing. So maybe it's actually padded armor? Who in their right mind wear's padded???
Ok, maybe I'm over-thinking this a little...