PURPOSE: To accomplish accurate and simple marking of an identification sign on a hot material after cutting, at the entrance of the cooling bed, by placing thereon an inflammable mount having the sign printed with a high temperature fused material such as powdered aluminum.
CONSTITUTION: An identification sign 14 is printed on a mount 10 made of an inflammable material such as paper with a high temperature fused material 16 such as powdered aluminum and alminum paint and the mount 10 is placed on the hot material 20 in such a manner as to have the printed surface facing the intended surface of the material. A pigment 16 deposits on the surface of the material 20 due to the heat retained (800W1000°C) while the mount 10 is burned by the heat. Thus, the marking of the indication sign is completed. This method enables clear marking simply and quickly thereby improving the working efficiency.