|An ungummed, imperforate souvenir sheet commemorates the participation of Imperial Post in the Last Saturday of the Month Bourse Day at St. Barbara's Greek Church, New York January 30, 1999. Licensed to BambooWeb by Imperial Post.|
The Imperial Post is the postal service of what can be called the micronation of The Empire of Upper and Lower, which comprises, is said to comprise, or claims (largely) almost all of Houghton County, Michigan, USA, part of Iron County, Michigan, and small areas in Brooklyn, New York and Calgary, Alberta. Although it can be characterised an issuer of artistamps, these artistamps have occasionally provided what has been in essence local post service within parts of Houghton, Michigan, all of Hancock, Michigan and the Copper Country Mall; airmail service has also been provided from Houghton to the Brooklyn "area" of the "Empire".
Imperial Post formerly also maintained and sold its artistamps from "offices abroad" in Concord, New Hampshire and St. Louis Park, Minnesota; both of these are now closed. Among the stamps it has issued are a souvenir sheet commemorating the Moscow International Forum of Art Initiatives in 2002. It also participated in the 1st International Artistamps Exhibition at the Barraca Vorticista in Buenos Aires, Argentina.
Imperial Post has issued a wide variety of types and formats of stamps, including gummed (and self-adhesive) souvenir sheets, a purely digital "stamp", and airmail stamps. The formerly "independent" micronation of Pinica, though incorporated into the Empire in 1984, continues to issue its own artistamps, which are valid for Imperial Post service. Although the Duchy of Natatoria was never independent from the Empire, it issues its own artistamps as well, which are likeweise valid. Pinica and Natatoria have also issued joint stamps under the name "Pinica-Natatoria".