Signs were first used in ancient Egypt and Rome. Generally, signs are meant to contain only shapes or drawings, from which a person draws information or indication of a certain object or a process. Industrial signs, however, are known to contain text that specifies the nature of the hazardous object or process, and also contains basic instructions or simple messages. Signs contain pictograms, which are standardized on an international or national level, so that signs manufactured by different companies would cause no confusion, and can be understood by everybody. Another factor that can change or influence the meaning of a sing it the color of its base or outline (orange commonly means attention or warnings, red - danger, etc.). Mega Depot supplies a vast array of signs, all for the best prices.