Information indicator and information indicating labels

A label for production control of rubber moldings, consisting essentially of:

• a. a single layer film substrate formed from a heat-resistant resin to which pigment has been added, the substrate having a first side and a second side which is on the opposite side to said first side;
• the first side defining an information indicating surface on which an identifiable indication which indicates specified information is printed, wherein microscopic irregularities of a prescribed roughness are formed on said information indicating surface so as to have a surface roughnesses with an arithmetical mean value of arithmetical mean roughness between about 0.5 and 5 microns, in which the size of said irregularities is set such that the indication printed on such information indicating surface is scarcely blurred or erased even under high temperatures and high pressures during vulcanization, and such that the recognizability and detectability of the indication on the rubber molding is not impaired;
• and
• b. a pressure sensitive adhesive layer which is provided on said second side of said film substrate, said pressure sensitive adhesive layer being adapted to be adhered to the unvulcanized rubber from which the rubber molding is formed.