 According to costumer Gloria Bava (qv), Neos original coat was  silver gray leather. It was changed because the directors wanted  something that was able to billow and float. There is a reference in  the script to "liquid sky"; a coat that would liquefy with the  surroundings and billowy. Even putting a wind machine under the coat  didnt move because leather was too heavy. Costumers finally changed  the fabric.