I picked up a couple of those FroggToggs Emergency Ponchos, with the really light weight wp/breathable fabric. I thought it might make a good material for rain mitts. Oddly enough, years ago I purchased patterns for over mitts by Controlled Exposure.
I have both the rain mitts by MLD and Zpacks, and they breath ok, but they don't fit very well. I hope the more contoured shape of the Controlled Exposure pattern will feel better.
I checked with my sewing machine and it can sew the 3/16" seam allowance on the lightweight material just fine, and after sewing I will come back with some 0.33oz cuben fiber tape to water proof the seams and provide some strength. The 3M 9460 tape I use for the tape sticks very well to the slick side of the FroggToggs material. I might have some wrinkles as it goes around curves and such, but it shouldn't be that bad.
As for durability, I plan on treating them with kid gloves. Any holes/wear areas can be patched with cuben tape. If wear is a problem, then I can make another pair with something more durable in the palm and thumb area.
Weight: I traced out the panels onto a piece, and without cutting them out, the fabric weighs 0.6oz for the pair of gloves. I predict the pair when done will weigh 0.5oz or less.