Granted Patent
Utility
US 5,499,757 · App. 08/232,894
Easy open, tamper evident envelope
Inventor:
Gordon E. Back
Patented Case
View Patent ↗
Granted: Mar 19, 1996
Filed: Apr 25, 1994
Inventor
Gordon E. Back
Assignee (at issue)
International Envelope Company
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.