Materials processing can require the flow of pastes to occur in two or three dimensions whereas predictive approaches are only available at present for simpler flows. Radial outflow of pastes between circular discs provides a suitable vehicle for further fundamental development and is also central to injection moulding fed by a central pipe. The purpose is to predict the pressure drop during the radial outflow of pastes into the space between two flat circular discs. Two theoretical approaches using paste rheological parameters are given but neither provides a complete description of behaviour. Certain phenomena encountered will need to be included in a more general approach. Thus paste/wall contact may be lost due to hoop strain and then shear stresses at the disc surfaces are not fully developed. The paste may also crack due to hoop tension.