Granted Patent
Utility
US 4,521,492 · App. 06/365,538
Light refractive coated paperboard
Inventor:
Robert L. Allen
Patented Case
View Patent ↗
Granted: Jun 4, 1985
Filed: Apr 5, 1982
Inventor
Robert L. Allen
Assignee (at issue)
Champion International Corporation Limited
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.