A conformable paste comprising porous agglomerates of carbon black dispersed in a paste-forming vehicle is disclosed. The paste is useful as an interface material for improving the thermal contact between two proximate solid surfaces, such as the surfaces of a heat source and a heat sink. Upon compression between the two solid surfaces, the paste forms a material that enhances the thermal contact between said surfaces. This invention also discloses a conformable interface material which, upon compression between two proximate solid surfaces, forms a material that enhances the thermal contact between said surfaces. This interface material comprises (i) a sheet and (ii) a conformable, spreadable and thermally conductive paste on each of the two opposite sides of the sheet, said paste comprising porous agglomerates of carbon black dispersed in a paste-forming vehicle. In addition, a method of providing a thermal contact between two solid surfaces is disclosed. This method comprises disposing between and in contact with said surfaces a material comprising: a conformable, spreadable and thermally conductive paste comprising porous agglomerates of carbon black dispersed in a paste-forming vehicle, and applying a pressure to cause said material to conform to the topography of said surfaces.