A thermal transfer film comprises a coloring layer formed on a substrate film via an intermediate layer, wherein the intermediate layer contains a thermally fusible substance and a non-transferable binder resin, the melt viscosity of the thermally fusible substance in the temperature range 15 to 25.degree. C. higher than the fuse peak temperature of the thermally fusible substance is in the range of 100 to 1000 mPas, the fuse peak temperature of the thermally fusible substance is in the range of 50 to 110.degree. C., the crystallization peak temperature of the thermally fusible substance is in the range of -20 to 100 .degree. C., the crystallization peak temperature of the thermally fusible substance is lower than the fuse peak temperature by 10.degree. C. or more, and the softening temperature of the binder resin measured by the ring and ball method is in the range of 130 to 400.degree. C. This thermal transfer film is capable of forming a printed product with a good printing quality.

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.