A feather duster is used to remove eraser shavings from pencil drafts and drawings.
Because the fixing power of pencil on paper is weak, if you try to dust off the shavings with your hands, the oil on your hands could rub off on the paper and spoil the drawing or its colors, and the friction could smear or smudge the pencil image. In contrast, with a feather duster, the shavings can be removed with the right amount of pressure without damaging the drawing.
The feathers on a feather duster are usually from the wings of ducks and other waterfowl, or a bundle of feathers from a chicken. There are also other instruments that are used for the same purpose such as drafting and design brushes which are brush-shaped tools with horse hair, goat hair or less effective nylon bristles.
When using a duster, it is best not to press too hard on the surface and to avoid using dirty dusters.
Feather dusters can be purchased at stationery and art supply stores, etc.