Underglaze Decorating Pencils (Lead Free) Now more intense, with better working qualities. Underglaze Decorating Pencils are ideal for shading, fine line drawing or identification. Apply the underglaze pencil to bisque ware to create a variety of unique decorative designs. After decorating, dust lightly with a brush to remove excess particles. Maximum firing temperature is Cone 10 for Blue, Black, and Green; Cone 5 for Brown and Yellow. Sponge on first coat of clear glaze lightly in order not to smear design. Let dry and brush additional coats of clear transparent glaze. This precaution is unnecessary if the glaze is to be applied by spraying, dipping or pouring. Pieces are fired to the maturing temperature of the covering glaze. When spray application of a covering glaze is desired, first refer to individual listing to be sure that it may be sprayed safely. Unlike regular pencils -- care must be taken in sharpening Underglaze Pencils. Do NOT use a pencil sharpener. It is best to sharpen them with a knife or blade. NOTE: The maximum firing temperature is Cone 10 for Blue, Black, and Green, Cone 5 for Brown and Yellow.