Carbonless duplication form set - has sheets coated with material having chromogenous reactive ingredient initially uncoloured

摘要

The carbonless duplicating system comprises two or more sheets on top of each other, each sheet being coated on both surfaces with a material having a chromogenous reactive ingredient, initially uncoloured. A reactive ingredient in each coating of one of the sheets gives a coloured tracing on the coating of a second sheet on coming into contact with it. The first sheet is above the second one, so that contact between coatings takes place when pressure is applied. The sheet comes into contact with the second side of the second one, producing a second coloured tracing.