No Carbon Required (NCR) Paper

A sheet of paper, used to make duplicate copies of written or printed material, whose back is coated with a layer of microcapsules that contain a dye in colorless form in a hydrocarbon solvent; writing or printing pressure breaks the capsules and releases the dye, which reacts with a clay or phenolic resin coating on top of a second paper sheet, located directly below the first, to produce visible color.