At present, the ink-jet printing medium is based on the multi-layer surface coating structure, which generally has two basic functional coatings, namely the solid ink functional layer and the ink absorbing functional layer. Solid ink functional layer product solutions form color images and generally contain positively charged components to adsorb negatively charged dye molecules. Ink-absorbing functional layer product solution is to absorb and accommodate the solvent in the ink, in the porous pigment based ink absorption layer, often choose silica, alumina, etc. as porous pigment particles, there is a certain gap between the pigment particles, the formation of a large number of micro-pores in the coating network, the ink-jet ink droplets play an adsorption role.