Most crossflow microfiltrations of suspensions of significant solids volume concentration exhibit non-Newtonian flow behaviour, and may lead to the deposition of appreciable cake depths. The cake depth may even extend to the full filter tube diameter, thus blocking any further filtration. Crossflow filtration modelling also requires knowledge of the cake depth, and the transmembrane pressure. Experiments have been performed for both the crossflow microfiltration of non-Newtonian talc suspensions, and an investigation of the pressures and flow rates in impermeable tubes of diameters similar to the crossflow filters. The investigation also illustrates how the transmembrane pressure drop can be corrected to take account of differences in cross-sectional area between where the pressure measurements are recorded and the filter flow channel. A method is demonstrated for the estimation of the depth of deposit on a fouled filter tube from pressure and flow measurements, when combined with a knowledge of the suspension rheology. The pseudo-equilibrium steady-state flux has been shown to correlate with shear stress at the filter or deposit surface, after the above corrections have been performed.