Following a brief review of past practices, an equation for the relationship between measured viscosity and volume solids is derived. The derivation of the equation is based on the concept of shear induced anisotropy, which is also presented. Using data developed on polystyrene and titanium dioxide dispersions, the equation is shown to be valid over a wide solids range. The equation allows the calculation of the degree of packing of the dispersed particles through the use of the relative shear volume. The equation and the shear induced anisotropy concept are then applied to the known properties of paper coatings. This discussion gives further insight into the hydrodynamics of blade coating and the nature of pseudoplastic and dilatant systems.