This document specifies the requirements for the exchange of data and information necessary for the definition of the aims for four-colour flexographic printing of packaging and publication materials, including newsprint. It is based on the use of colour characterization data to define the colourimetric printing aims and includes appropriate assignment of responsibility for and recommended tolerances on critical parameters of the flexographic printing process. This document is directly applicable to: — publication flexographic printing including magazines, catalogues and commercial materials and packaging flexographic printing including labels, boxes, and flexible packages; — half-tone and continuous tone proofing processes that predict the colourimetric results of flexographic printing. Guidance is also provided concerning the definition of spot colours used in flexographic printing.