Disposable filter attachment for smoking articles

A disposable filter for attachment to a smoking article, such as a cigarette, by a user, comprising a filter element having a mouth end and an insertion end and a cross-sectional area, said filter element comprising first and second separately formed filter segments positioned in longitudinal abutting relation with the second filter segment at the mouth end of the filter element, said first filter segment comprising a gathered web of a paper containing a carbonaceous material, the paper being gathered so as to form a plurality of longitudinal channels each having a longitudinal axis, each channel being open from end to end of said first filter segment along the longitudinal axis thereof, each channel further having a cross-sectional void area, the total cross-sectional void area of said open channels comprising more than about 5 percent of the cross-section area of the first filter segment such that at least some mainstream smoke from a smoking article attached to the insertion end of the filter element passes through the open channels of the first filter segment, the cross-sectional area of the first filter segment being entirely filled with the carbonaceous paper and said open channels, a hollow insertion tube formed longitudinally adjacent the first filter segment at the insertion end of the filter element for axial insertion of a smoking article by the user, said insertion tube having an axial length and a diameter sufficient to receive and support a smoking article therein, the total pressure drop across said two segments being sufficiently low as to have a minimal effect on the pressure drop of the smoking article to which the disposable filter is attached.