Heat sensitive inks are disclosed that reduce kogation in the print heads of thermal ink jet printers. The ink incorporates heat sensitive colorants/sublimation dye solid particles that are larger in size but smaller in quantity than particles that are not heat sensitive at the operating temperature of the heating elements. The smaller particles do not contribute to kogation, whereas the larger colorant particles contribute to kogation if they contact the heating element of the print heads. The smaller particles move more rapidly toward the heating element as the thermally induced bubble collapses and provide a barrier between the heating element and the heat activated or heat sensitive colorants/sublimation dye solids (hereinafter heat sensitive colorants).