An ink for ink jet printing includes particles of an emulsifiable dye-polymer resin dispersed in a liquid vehicle, wherein the emulsifiable dye-polymer resin includes a dye chemically attached to the polymer resin. The polymer resin contains a base chain, such as polyester, having attached thereto hydrophilic groups, such as alkali sulfonated groups, for emulsifying the resin in water. The dye may be attached within the base chain itself, or attached to the base chain as a side chain component.