The invention provides a method for controlling the width of a plurality of extruded filaments comprising providing a polymer supply and an extrusion die comprising a plurality of extrusion capillaries and a plurality of counterbores allowing fluid communication between the extrusion capillaries and polymer supply, providing an adjustable insert for interrupting fluid communication between the polymer supply and at least one extrusion capillary, providing at least one fluidized polymer, conveying the polymer through the polymer supply, counterbores and extrusion capillaries to extrude a plurality of filaments, and interrupting the fluid communication between the polymer supply and at least one extrusion capillary by adjusting the insert. An apparatus for extruding filaments is also provided, comprising an extrusion die, polymer supply, extrusion capillaries, counterbores allowing fluid communication between the capillaries and polymer supply, and an adjustable insert for interrupting fluid communication between the polymer supply and at least one extrusion capillary.