Abstract
The diffusion of ink in water was investigated. Both stamp ink and Quink blue ink were chosen for the analysis. The displacement of the diffused ink front was measured at temperatures of 10-30°C. The experimental data of the ink front were in good agreement with the theory of diffusion. The diffusion coefficients satisfy the Arrhenius plot, and the activation energy is smaller for the Quink blue ink than for the stamp ink. The mechanism of the ink diffusion is explained by the kinetics of viscous flow.