Those of you using thermal reflective emergency blankets and such
might want to take a look at the Adventure Medical Bivvy Sack.
The blankets they make out of Thermo-Lite (a non-woven polester, like
Neet Sheet) are both soft and quiet. Many gear stores carry this
brand so you might be able to have a look at one locally (that's
where I saw the bivvy). One of these weighs about the same as a silk
liner, but is probably more effective in retaining warmth.