Granted Patent
Utility
US 4,842,950 · App. 07/199,011
Overlay proofing film
Inventor:
O. Alfred Barton
Patented Case
View Patent ↗
Granted: Jun 27, 1989
Filed: May 26, 1988
Inventor
O. Alfred Barton
Assignee (at issue)
Hoechst Celanese Corporation
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.