On dried green bean coffee, the thin inner-parchment layer that clings to the bean and lines the crease on the flat side. Silverskin becomes chaff and falls off the bean during roasting. It is a fine inner layer coating the seed, between the thicker parchment and the bean. Formerly, dry mills would polish coffee to remove the silverskin, since the coffee looked better to the buyer. But this generates heat that damages cup quality, so the polishing step is discouraged.