A pressure and heat-sensitive composition comprising chromogen-containing pressure-rupturable microcapsules and heat-sensitive color developer useful for verification of document authenticity system when applied as a localized coating on documents, such as checks and prescriptions. Quickly striking the...http://www.google.com/patents/US5595955?utm_source=gb-gplus-sharePatent US5595955 - Verification method using pressure and heat-sensitive chromogenic system
