The present invention is drawn to ink sets, methods of electronically sensing printed images, and ink-jet printing systems. In one embodiment, an ink set for ink-jet printing can include a cyan ink including cyan colorant, a magenta ink including magenta colorant, and a yellow ink including yellow colorant. All three inks of the ink set can include an infrared absorbing dye and have an overlapping infrared absorbance range with respect to one another.