A method of producing a coating composition in an in-store tinting machine comprising the steps of selecting a base paint, adding at least one additive to the base paint, adding at least one colorant to the base paint, the at least one colorant being selected from a range of colorants in the in-store tinting machine, mixing the base paint, the at least one colorant, and the at least one additive so as to produce a coating composition, in which the additive is not a base paint or a colorant from the range of colorants in the in-store tinting machine.