After drying, carve on the wax layer (to penetrate the wax layer to the crucible surface), and then use the filter paper sheet moistened with qingfusuan to apply on the carving, leave it for about 10min, rinse the residual acid with water, and scrape off the wax layer can be. Rot carving with qingfusuan, according to 10g qingfusuan add 3ml concentrated sulfuric acid, made of mixed acid use, rot carving effect is very good.

Writing on the crucible with a solution of ferric chloride, and then burned at about 800C for an hour, so that a long time to mark. Numbered with blue ink containing trivalent iron ions, and then heated at the desired temperature to burn. Scorching is generally carried out in a high-temperature electric furnace, into the cold hearth gradually warmed up, or the crucible into the hearth has risen to a higher temperature preheating a little, and then put into the hearth. Generally 0.5H (1.0H for new crucible) is needed.