Abstract: Provided is a data carrier (1) extending along an extension direction (E) comprises at least one first colour element (2), wherein the first colour element (2) exhibits an appearance under a first illumination and/or exhibits an appearance under a second illumination being different from the first illumination, at least one second colour element (3), wherein the second colour element (3) exhibits an appearance under the first illumination being different from the appearance of the first colour element (2) under the first illumination and/or exhibits an appearance under the second illumination that is different from the appearance of the first colour element (2) under the second illumination.

Abstract: A variable colorant blender is provided for use as adjunct to an airbrush (A) or other spray gun. It includes a plurality of metering valves or similar devices which are actuatable wholly independently of one another for enabling the user to obtain and continuously change any colorant blend and also to perform a rapid rinsing. In preferred embodiments electric metering valve actuators are provided, which are energized by electronic circuit means contained in a control box (16) remote from that portion (10) of the blender which is affixed to the airbrush or other spray gun in replacement of the usual colorant-containing vessel 1, such control box having slides (41) for presetting and changing the proportions of colorants in the discharged blend, and possibly also a push-button (42) for controlling the amount of cleaning liquid (solvent).