Deep-dyeing conjugate filaments are melt-spun by merging molten sub-streams of incompatible polymers to form combined streams, then quenching the combined streams to form the conjugate filaments. The filaments are preferably cold drawn prior to winding, increasing the bulk level in a fabric containing the filaments and increasing the dye stability of the filaments. When the sub-streams are merged outside of the spinneret, the filaments split into the sub-filaments upon exposure to boiling water while under no tension. When the sub-streams merge within the spinneret, the filament is not readily split into sub-filaments, but forms a helically crimped filament.