To improve print quality, it is important to analyze the mechanisms of ink fixation on paper. First of all, the three dimensional (3D) fluorescence spectra of excitation and fluorescence were obtained by a fluorescence spectrophotometer. The optical condition for observing ink-jet prints by CLSM was found through the characterization of three-dimensional fluorescence spectra of ink. The distributions of dye-based and pigment-based ink-jet inks were observed as fluorescence images by CLSM, whereas cross-sections of these ink-jet prints prepared by FIB were observed as light-reflected images by the optical digital microscope. By comparing light-reflected cross-section images of prints with reconstructed images of prints by CLSM, the distribution of ink-jet inks on the glossy photo ink-jet paper could be evaluated. In the case of pigment-based inks, the inks were fixed on the paper. On the other hand, in the case of dye-based inks, the inks were penetrated into the ink acceptable layer on the paper. In addition, inks tended to penetrate to depth proportional to the diameter of the ink dot.