A novel formulation for thick-film graphite sacrificial pastes is studied in this paper. It is composed of coarse graphite powder (grain size: 25 μm), dispersed in a vehicle consisting of polyvinyl alcohol (PVA) dissolved in a propylene glycol (PG)–glycerol (G)–water mix, which is not aggressive to thin LTCC sheets. The presented sacrificial paste has been successfully applied for fabrication of thin (<50 μm) membranes and microchannels in low temperature co-fired ceramics (LTCC) substrate. The properties of the graphite-based paste have been examined using thermo-gravimetric analysis (TGA), differential thermo-gravimetric (DTG) and differential thermal analysis (DTA). The obtained membranes and microchannels have been investigated using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and optical profile measurements gauge.