04936607 is referenced by 11 patents and cites 18 patents.

Methods for preventing or reducing the likelihood of successful alteration of information printed on a document, wherein a detectable substance is released from ruptured microcapsules onto the document in image areas. The substance penetrates through the document to form a confirming image on the reverse surface. Another detectable substance of lesser penetrating ability simultaneously may be released onto the document in the image areas. Spreading of the first substance outside the boundaries of the image area created by the second substance may produce a halo effect around the image area. Documents as treated by the methods are disclosed, as well as articles comprising a document to be treated in contact with a sheet coated with the detectable substance. The first substance is microencapsulated, the second substance may or may not be microencapsulated.

Title
Security for images formed by impact based systems
Application Number
7/149080
Publication Number
4936607
Application Date
January 27, 1988
Publication Date
June 26, 1990
Inventor
James M Raby
Youngstown
NY, US
Robert W Brunea
Portland
OR, US
Agent
Cushman Darby & Cushman
Assignee
Moore Business Forms
IL, US
IPC
B42D 15/00
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