What is NCR Paper?

What is NCR Paper?
Also known as “Carbonless copy paper”
NCR paper was intended to replace an earlier version of copy paper know as carbon paper. It’s used to make a copy of an original handwritten or impact printed paper form. Developed by the NCR corporation as a clean, biodegradable, manual, non-mechanical or non-electronic document replication system.
How’s it work?
NCR paper is made up of one or more sheets of paper which are coated with very tiny micro-encapsulated dye or ink droplets and reactive clay. Where “micro-encapsulated” or also known as “microsphere” and where “clay” as fine silica sand.
The backside of the top sheet is coated with the very fine ink droplets. The top of the next consecutive sheet or sheets are coated with the clay. When force or pressure is applied to the top part of the form by hand writing or impact from an impact printer, the fine ink droplets burst and spill the tiny amount of the dye or ink onto the clay making a permanent mark. The key is to remember that the size of the ink droplet is around 2uM (uM is micrometers or 10 to the -6 power).
Most NCR forms are no more than 5 pages. So the very top page would not have any clay, and the very last sheet-back would have no ink droplets.
Composition of dyes and chemicals
Some dyes are, but not limited to- crystal violet lactone. Other dyes and supporting chemicals used are PTSMH (p-toluene sulfinate of Michler's hydrol), TMA (trimellitic anhydride), phenol-formaldehyde resins, azo dyes, DIPN (diisopropyl naphtalenes), formaldehyde isocyanates, hydrocarbon-based solvents, polycyclic aromatic hydrocarbons, polyoxypropylene diamine, epoxy resins, aliphatic isocyanates, Bisphenol A, diethylene triamine, and others.
Risk
Rare- contact with NCR could cause dermatitis (irritation of the skin, red itchy)
Invented by David Steinhardt and patent.