Nice.Accessories brand Coperni debuted a bag at Paris Fashion Week that\s made of 99% air and 1% glass. It weighs 33 grams and was constructed out of silica aerogel, which is the lightest solid on Ea Accessories brand Coperni debuted a bag at Paris Fashion Week that's made of 99% air and 1% glass. It weighs 33 grams and was constructed out of silica aerogel, which is the lightest solid on Earth.