Not all that glitters is gold. Some are textiles, and some of those are uber-sexy like these Granite Gear Uberlight DrySacks. These things are ridiculously light, ranging from an anorexic half an ounce for the 4.5"x7"x17" 7L to .75oz for the 6"x8.75"x 22.5" 13L. Crazy light.
And crazy thin, too. The Uberlights are like giant condoms, only they don't smell like wet latex because they're made of some kind of translucent PVC-free fiber-based film developed in Middle Earth for magic elfin sailboats. You can't even remember how to do long division, so don't pretend you understand the technology. Just know that it works really well.
The Uberlights use a standard roll-top closure and have a rectangular bottom panel; if you pack carefully you end up with a rectanglish package that wastes a little less space in your pack. You can make out the contents through the material, which – to answer the big question – is tough as nails. We tried to put our bag-lady fingernails through it but couldn't. Note that these bags come with a paper-thin patch kit that is easy to mistake for a quality control ticket: don't throw it away.
They really are waterproof, and we didn't hesitate to entrust our camcorder to it. Well, OK, at first it was our friend's camcorder, but now we won't hesitate, and for general hiking and camping use you shouldn't either. For expedition kayaking you'll want something beefier to withstand big loads and constant abrasion, but even on the open water the Uberlight will still make a great deck bag.