A synthetic polymer filament is characterized by a four-sided void that extends centrally and axially through the filament. Each apex of the void extends toward the approximate midpoint of one side of the exterior configuration of the filament. The four-sided void has a modification ratio in the range from about 1.2 to about 2.0 and occupies from about five percent 5% to about thirty percent 30% of the cross sectional area of the filament. A spinneret plate for producing the thermoplastic synthetic polymer filament has a cluster of four orifices centered about a central point. Each orifice includes a generally isosceles triangle-shaped major portion from which extends a pair of legs, each leg of one orifice being spaced from the leg of an adjacent orifice to define a gap therebetween.