Hexagonal boron nitride (hBN) is a layered material possessing extraordinary physical properties such as ultrahigh chemical stability, high electronic bandgap (about 6.5 eV), good thermal conductivity and negative electron affinity. Also known as “white graphite”, due to the similar (hexagonal) crystal structure, hBN powder provides excellent lubricating properties being commonly used in industrial applications. In the last years, hBN has emerged as an important material for deep ultraviolet photonics and as well as solid-state neutron detectors.hBN has traditionally been considered as a material of choice in thermal-management applications and dispersed in polyimide and epoxy matrix to give nanocomposite films with superior thermal transport performance without degrading mechanical properties (up to 15 vol%).