Carbonless copy paper is a type of hidden color copy paper that has the function of direct copy and direct color development. Its color development is mainly due to the external force, which causes the force sensitive pigments and oil solution in the microcapsules to overflow and come into contact with the color developer, resulting in a staining reaction and thus playing a role in replication. Mainly used for multi sheet forms, bills, continuous financial bills, general business financial bills, etc.