The present disclosure relates to a filamentary structure manufactured during 3D printing by liquid deposition modelling, the filamentary structure comprising a continuous strand comprising a matrix material and filler particles, wherein the filler particles comprise hexagonal boron nitride particles comprising hexagonal boron nitride platelets. The present disclosure further relates to a 3D printable ink composition for manufacturing said filamentary structure, to a 3D printed component part formed from said filamentary structure, to a 3D printing method for making said 3D printed component part, and to the use of said component part.