The Type I 1c imperforate only comes from one position on the five plates used
to print the imperforate stamps -- Position 7R1E, or the seventh position in the
top row of the right pane of the first plate. Due to difficulties in creating
the plates, all 999 other positions are other types. An explanation of the 1c
types can be found in the Siegel Encyclopedia.
Because of the
significance attached to the outer portions of the 1c 1851 design, rare types
that have been carefully cut apart, so as not to impinge on any part of the
design, are extremely desirable. The narrow spacing between stamps in the sheet
and the users' indifference to the outlying ornamentation during separation are
factors that contributed to the great rarity of four-margin copies. Examples of
Position 7R1E (Scott 5) with large right and bottom margins, where there was
very little space between it and the adjoining stamps, are true
This census was originally published in printed form by noted
philatelist Jerome S. Wagshal.