"Ah, carbon copies, yellow, blue, green 'flimsies', like sheets of tissue paper, and the further down the pile you were the fainter they were!"

No, that was the scientific marvel that was known as <"no carbon required" paper> the replaced carbon copies.

Carbon paper had an oily-feeling coating on one side. You put it between 2 sheets of normal paper, wrote (or typed) on the top sheet, and the carbon coaring made a copy on the lower sheet.