An ink set is provided which produces a printed article having excellent physical durability. The ink set contains a first liquid composition containing a reactive carbonyl group and a second liquid composition containing a co-reactive amine group, at least one of the first liquid composition and the second liquid composition further containing a coloring material. When the two inks are printed on a substrate in at least a partially overlapping arrangement, the reactive amine and reactive carbonyl species can crosslink to form a more durable image.