Patent ID: 7380415

Claim:
A method of making a decorative glass ceramic panel for a cooking unit, wherein said decorative glass ceramic panel is not transparent and comprises a glass ceramic panel having a predominant crystalline phase of keatite mixed crystals and a colored full-surface decorative coating provided on a cooking-surface side of the glass ceramic panel, said decorative coating covering at least 80 percent of the cooking-surface side of the glass ceramic panel and having a different color than said glass ceramic panel; said method comprising the steps of: a) making a translucent or opague white glass ceramic panel comprising said predominant crystalline phase of said keatite mixed crystals with a smooth side; b) applying said colored full-surface decorative coating on said smooth side of the translucent or opague white glass ceramic panel so that said colored full-surface decorative coating covers at least 80 percent of the smooth side; and c) baking or burning in at least one ceramic pigment included in the full-surface decorative coating; wherein said colored full-surface decorative coating comprises a glass flux and up to 30 percent by weight of said at least one ceramic pigment so that said colored full-surface decorative coating has a color shade with a lightness value L*>70, and said at least one ceramic pigment is selected from the group consisting of ZrSiO 4 , TiO 2 , CeO 2 , yellow pigments containing at least one Zr/Sr/Pr oxide and brown pigments containing at least one Zn/Cr/Fe oxide; and wherein said lightness value L* of said color shade of said full-surface decorative coating is less than a lightness value L* of a color shade of said white glass ceramic panel, whereby said color shade of said full-surface decorative coating cooperates with said color shade of said white glass ceramic panel to reduce conspicuousness of usage marks, metal rub-off, scratches and fingerprints and prevent observation of a cooking device interior.