The fiber mat formation and filtration properties of paper pulp suspensions are of considerable importance to the paper industry to predict properties of the paper formed from the pulp suspensions. The objective of this work is to model the filtration process and to compare the model results with experimental measurements. The long-term goals of this work are to develop a better understanding of the mat formation and filtration process so as to better understand the measurements from static formers and thus reduce waste from inferior pulp suspensions. Filtration of filler particles within cakes formed from pulp suspensions is modeled using principles of volume-averaged continuum theory applied to cake filtration of compressive fibrous mats. The retention of the filler particles in the fiber mat is significant to the paper industry because the filler particles contribute to the mechanical properties of the paper products. (C) 1997 Elsevier Science B.V.