A substrate comprising a surface on which is coated encapsulated N-(monosubstituted)dithiooxamide compound of the formula: ##STR53## wherein R3 comprises: (a) an alkyl or aralkyl group having 11 or more carbon atoms; or(b) a group of the structure --R4 --Y--R5 wherein:(i) when Y is a functional group selected from the group consisting of --N(R6)C(O)--, --C(O)N(R6)--, --N(R6)C(O)O--, --OC(O)N(R6)--