Check paper that is protected against forgery and tampering

摘要

A check paper is being described which is protected against falsifications and forgeries. Crushable micro capsules are being embedded in check paper which contain on one hand a leuco ink and on the other hand a color acceptor. The color acceptor can also be stored in the body of the paper without the use of micro capsules. The leuco ink and the color acceptor react together under color development or color changes if the micro capsules burst through imprinting or other local pressure application to the paper surface. Thus, a character written on the paper surface becomes visible within the body of the paper and cannot be forged anymore.