A masterbatch is a concentrated mixture of pigments and / or additives blended and extruded together in a carrier matrix, such as resin or wax, that is used to add these mixed additives to a final plastic product. The additives may be used for colouring (a "colour masterbatch") or for imparting other properties (an "additive masterbatch"). The typical alternative to using a masterbatch is to compound the plastic from raw undiluted additives.