This paper presents experimental data on VRM of synthetic multidomain titanomagnetites under three aspects: (1) The variability of the acquisition and decay viscosity coefficients, Sa and Sd, by the measuring procedure, (2) the dependence of Sd on the titanium content x in the system Fe3-xTix 04 at 77 K and 300 K, (3) the viscous behavior of magnetization under an unaxial stress parallel and perpendicular to the direction of the applied field. The experiments indicate a predominant influence of the diffusion after-effect.