A hermetically sealed glass package preform is provided comprising a glass substrate; a frit comprising 65-100 wt. % of a base glass and about 0-35 wt. % of a filler; wherein the base glass comprises: about 0-5 mole % K2O; about 0-35 mole % Sb2O3; about 0-20 mole % ZnO; about 10-40 mole % P2O5; about 10-60 mole % V2O5; about 0-5 mole % TiO2; about 0-5 mole % B2O3; about 0-5 mole % SiO2; about 0-5 mole % WO3; and about 1-10 mole % of a metal oxide selected from the group consisting of Fe2O3, Nd2O3, La2O3, Ce2O4, Pr6O11, Er2O3, and CeO2; wherein the base glass has a mean particle size distribution of less than about 3 μm; and wherein the filler has a mean particle size distribution of between about 3 and 7 μm. The frit is sintered in an atmosphere less oxidizing than air at a temperature of between about 390° C. to 415° C.