C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
C03C8/14—Glass frit mixtures having non-frit additions, e.g. opacifiers, colorants, mill-additions