The RBI for long had been planning to launch plastic currency notes after field trials. It had also received tender bids for one billion notes. In February 2014, the government had informed Parliament that one billion plastic notes of `10 denomination would be introduced in a field trial in five cities selected for their geographical and climatic diversity. The selected cities were Kochi, Mysore, Jaipur, Shimla and Bhubaneswar.Plastic notes have an average life span of about five years and are difficult to imitate. Also, currency notes made of plastic are cleaner than paper ones.