GR10-J
DraftDescription
GR10-J is a Cone 10 reduction, Ravenscrag Slip-based silky matte glaze. It is formulated for high stability, resisting crazing, cutlery marking, and surface staining on most stoneware bodies. The incl
Original Author
Tony Hansen
Usage Instructions
GR10-J is a Cone 10 reduction, Ravenscrag Slip-based silky matte glaze. It is formulated for high stability, resisting crazing, cutlery marking, and surface staining on most stoneware bodies. The inclusion of calcined kaolin is mandatory to prevent excessive drying shrinkage; raw kaolin is not an acceptable substitute. If Gerstley Borate or its commercial substitutes are unavailable, an equivalent boron source must be utilized. While the glaze is inherently durable, potential crazing may occur on certain stoneware bodies following decal firings. The glaze may be tinted using metal oxides: 1% cobalt oxide and 0.2% chrome oxide produce a 'robin's egg blue' (best suited for buff stoneware), while 0.5%–1% iron oxide produces a 'bamboo' coloration. To achieve a whiter finish or to match the aesthetic of G2571A, 3–5% Zircopax may be added.