Here's a few quick projects I did recently from left over primaloft (1.8oz), $1/yd 1.7oz ripstop and $1 space blanket. All in all, they came out really nice and functional.
Mylar VB jacket weighs in at 1.75oz. Could be lighter w/o zipper (.4oz). Tried several sewing methods on the mylar, but simply taping with scotch tape surprisingly held the best.
Double layer of 1.8oz primaloft. Weight is 2.15oz.
Single layer of 1.8oz primaloft. Weighs 1.45oz