An overview of spectroscopic methods to investigate physical processes specific to the water-based ink/substrate interaction is made in this work. Optical techniques (as VIS reflectometry, IR-ATR and spectroellipsometry) and electrical impedance spectroscopy have been employed to study physical phenomena that describe the interaction between water-based mixtures and the substrate for printing; the latter can be absorbent (porous) or non-absorbent of liquid. Therefore, evaporation of aqueous mixtures and/or liquid penetration in porous paper are the main subjects of these studies. After brief introduction in each method, examples of various particular cases are presented and analyzed: evaporation of pure liquids and mixtures, water penetration into paper of various thicknesses, the penetration of different liquids into plain paper. The method of spectroellipsometry was used to characterize the coating of the coated paper for printing industry.