T68 is a pyrolytic graphite product, that is manufactured when a hydrocarbon gas is decomposed at a vacuum at high temperature. Carbon atoms form into a structure that in one direction consists of planar layers of hexagonally arranged carbon atoms and in the other perpendicular direction consists of randomly oriented atoms. This means that the thermal properties of T68 are highly anisotropic since phonons can propagate rapidly along the close-packed directions but slower plane to plane.

