Carbonless Copy Paper, more commonly known in the printing industry as NCR Paper (No Carbon Required) was first produced by the NCR Corporation. Before this the only option was to write documents more than once or use messy Carbon paper which was inserted inbetween the sheet being written on and the required copy below, often ending up with the user having blue fingers. The invention of NCR Paper made duplicating, triplicating and even quadruplicating hand written and printed documents easy and clean. NCR Paper is commonly used for Invoices, Receipts and any other document where duplication is required. There is an array of colours available such as white/yellow/pink/green/blue, in most instances white is the top copy and subsequent colours are beneath dependant on the number of duplicated pages required. For example; If you require 2 copies of a document being written/printed, you would have a white top part and 1 coloured second part below, this is called 2 Part or Duplicate. For 3 copies, you would have a white top part and 2 coloured parts below, this is called 3 Part or Triplicate. For 4 copies, you would have a white top part and 3 coloured parts below, this is called 4 Part or Quadruplicate. NCR Paper is usually supplied to the end user collated into Pads/Books which are bound into sets using glue or staples, Loose Sets or Continuous Forms are also widely used for use in printers.