Since August 1991, collectors of modern US stamps have known of two distinct types of the intaglio printed Mount Rushmore coil stamp (Scott 2523, Krause-Minkus 945).

These stamps primarily have been differentiated by the tagging seen under short wave ultraviolet light.

The commonly found type exhibits tagging which looks mottled/non-uniform under short wave ultraviolet light.  The second type shows a solid/uniform tagging on whiter paper and is often referred to as "Lenz" paper.

The June 1999 issue of the Bureau Issues Association (BIA) journal, THE UNITED STATES SPECIALIST, contains an article by Ken Lawrence which fully explains these two different stamps.  The article provides a basis for updating catalog listings of the Rushmore stamp and also for reexamining the descriptions and terminology used in listing other modern US issues.

Thanks to both Ken Lawrence and the Bureau Issues Association for permission to use this copyright six page article on my web site. 

Want a postally used example of a coated (Lenz) paper Rushmore?  Click here to send me an e-mail with your name/address and a cover will soon be in the mail to you.