LA-ICP-MS analysis of the chemical composition of the exterior slips and red and black pigments used for painted decoration of the three Postclassic Maya slipped ceramic wares suggests that the Itzá and Kowoj used different pigments for exterior slips and decorative motifs. Additionally, different slips and paints were used depending on vessel form and decorative program (red, black, or red-and-black painting or incising). When examined with previous ceramic paste chemical analyses, the data aid in better understanding the changing socio-political alliances and dominance relations in central Petén at the eve of Spanish contact.