The present disclosure generally relates to integrated core-shell investment casting molds that provide an integrated ceramic filter. These integrated core-shell investment casting molds also provide filament structures corresponding to cooling hole patterns on the surface of the turbine blade or stator vane, which provide a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.