Feathers will be lighter than vanes, if that is what you are striving for.

You can find some smaller feathers which wouldn't weigh much (I saw on Lancaster Archery Supply a 1.75" feather right at 1.5 grains)....or just look around for the lightest vane possible if you prefer vanes over feathers. (1.5" Flex Fletch was nearly 2.8 grains)