Abstract: A cathode ray tube includes a panel having an inner surface and an outer surface and a funnel connected to the panel having a neck portion dimensioned to house an electron gun. A single strip of synthetic resin material is coated on a predetermined area of the panel. The synthetic resin includes intaglio in the form of a bar code. The heat-resistant synthetic resin material consists of silicone rubber or consists essentially of a silicone-modified vinyl resin and aluminum. The bar code is undamaged by heat, even during a heating process of several steps, e.g., a baking process, so that the bar code and sheet can be formed during the initial steps of manufacturing the cathode ray tube. Accordingly, since the bar code is present throughout the CRT's manufacture, product management can be done all along the assembly line.