Plume n.
A fine white dust that develops on a properly humidified, aged cigar.
Plume - sometimes called fumée - is the crystalline residue of oils that have migrated to the surface of the wrapper during long, stable aging. It indicates a cigar that has been stored well and is a positive sign. Plume is fine, dust-like and brushes off easily. It must not be confused with mould, which is fuzzy, blue-green or grey, and ruins the cigar.