A method of providing or identifying one or more ink or coating composition(s) suitable for food contact, said method comprising the steps of: (i) providing one or more colourant(s); (ii) identifying the substances and any impurities in said colourant(s), wherein said identification comprises subjecting said colourant(s) to an extraction test; (iii) establishing a specific migration limit for each of the substances identified in step (ii); (iv) formulating said one or more colourant(s) into said ink or coating composition, and calculating the proportion of each of the substances identified in step (ii) which is present in a finished printed layer derived from said ink or coating composition; (v) performing a worst-case calculation by assuming that 100% of each of the substances identified in step (ii) migrates to a foodstuff when contacted with a finished printed layer derived from said ink or coating composition; (vi) evaluating whether said worst-case calculation in step (v) for each of the substances identified in step (ii) satisfies the criterion of being equal to or greater than the specific migration limit from step (iii), and if said criterion is satisfied for any of said substances then subjecting said ink or coating composition to migration testing; (vii) empirically determining by chemical analysis the migration level (M L) of each of said substances identified in step (ii) in one or more migration test(s); (viii) evaluating whether the migration level (M L) measured empirically in step (vii) for each of said substances in said ink or coating composition satisfies the criterion of being less than the specific migration limit established for that substance in step (iii), (ix) selecting as an ink or coating composition suitable for food contact those ink or coating composition(s) for which every substance contained therein satisfies the criterion in step (viii); (x) optionally selecting those ink or coating composition(s) containing one or more substance(s) which fail the criterion in step (viii) to be an ink or coating composition suitable for food contact only in restricted quantities. (i) providing one or more colourant(s); (ii) identifying the substances and any impurities in said colourant(s), wherein said identification comprises subjecting said colourant(s) to an extraction test; (iii) establishing a specific migration limit for each of the substances identified in step (ii); (iv) formulating said one or more colourant(s) into said ink or coating composition, and calculating the proportion of each of the substances identified in step (ii) which is present in a finished printed layer derived from said ink or coating composition; (v) performing a worst-case calculation by assuming that 100% of each of the substances identified in step (ii) migrates to a foodstuff when contacted with a finished printed layer derived from said ink or coating composition; (vi) evaluating whether said worst-case calculation in step (v) for each of the substances identified in step (ii) satisfies the criterion of being equal to or greater than the specific migration limit from step (iii), and if said criterion is satisfied for any of said substances then subjecting said ink or coating composition to migration testing; (vii) empirically determining by chemical analysis the migration level (M L) of each of said substances identified in step (ii) in one or more migration test(s); (viii) evaluating whether the migration level (M L) measured empirically in step (vii) for each of said substances in said ink or coating composition satisfies the criterion of being less than the specific migration limit established for that substance in step (iii), (ix) selecting as an ink or coating composition suitable for food contact those ink or coating composition(s) for which every substance contained therein satisfies the criterion in step (viii); (x) optionally selecting those ink or coating composition(s) containing one or more substance(s) which fail the criterion in step (viii) to be an ink or coating composition suitable for food contact only in restricted quantities.