plate number 20079
APNSS is organized to support stamp collectors interested in plate
number singles and other marginal markings.
is the serial number of a printing plate. It is printed in the
or border of a
of postage stamps. From the early days of U.S. stamps, plate numbers
generally appeared in the middle of the selvage. For example, plate
number 20079 appears on the right selvage of the 65¢ Graf Zeppelin stamp shown
stamp printings in the 1930s, plate numbers were generally printed in the
corner of each pane. Plate number 22206 appears in the selvage of
the 50¢ Taft stamp from an upper left pane, shown below. Identical
stamps from the upper right, lower left and lower right panes would make
up a complete matched set of all positions for this issue.
plate number single 22206
From 1966-1981, the
post office often printed a separate plate number for each color that was used in
the printing process. Some collectors felt that this often required a
large investment, as these issues were traditionally collected in
of 10, 12 or 20 stamps or even the entire pane. Plate number single
collectors collect these issues in strips or as singles.
13¢ Olympics error (no perforations),
showing 5-digit plate numbers for each color used in the printing process.
Beginning in 1981, the
post office started reducing the now 5-digit plate number to a single
digit for each issue, generally starting with 1. Multiple plates
used to print multiple colors could now be represented by single digits in
each ink color used, such as 1111.
$10.75 Express Mail stamp, plate
#P11111 showing a single digit for each color used in the printing
Plate numbers also
began to be printed on the face of
coil stamps, introducing a whole new
collecting interest. Previously, plate numbers were trimmed away
from coil stamps as part of the printing and coiling process. (Some
examples of partial plate numbers appearing on poorly-centered older coil
stamps can be found on the
23¢ First Class Presort stamp, plate
#1111 showing a single digit for each color used in the printing process.
At the same time,
printing contracts were opened up so that private security printers could
bid on and print U.S. stamps. (Virtually all U.S. stamps from 1894 to the
1980s were printed by the Bureau of Engraving and Printing or BEP, a division of
the U.S. Treasury Department.) A letter prefix was added to the plate
number to designate the
A, B, C, D, G, K, M, P, S, U and V have been used to date, as well as T on some BEP-printed test
coils. X is also used on USPS sample images.
In the 1990's, more and
more U.S. stamps were issued in the self-adhesive format. The last
true traditionally-gummed commemorative stamps were the 34¢ Enrico Fermi and
James Madison issues of 2001. Although it is still possible to
collect used coil plate number singles, where the plate number is printed
on the face of one stamp in the coil at regular intervals, it is very
difficult to collect used sheet and booklet self-adhesive stamps. To
do so, the sender of a sheet stamp -- almost always a stamp collector --
would have had to carefully remove from the backing and place on the
envelope not only the self-adhesive stamp itself, but also three bits of
selvage, one of which includes the plate number that was printed in the
margin. The recipient of either would need to save the used plate
number single "on cover" or "on piece," as any attempt to soak the stamp
off the envelope would permanently separate the stamp from the
all-important selvage and plate number. Used plate number singles
for modern self-adhesive stamps are almost always philatelically
contrived. Modern self-adhesives are generally collected as mint
examples, on their original backings as issued.
Due to changes in paper
manufacturing and USPS requirements, some issues are notoriously difficult
to soak off of their backing paper. In fact, many are
downright impossible, as they were manufactured without the water-soluble
layer of glue that allows this to happen. Many collectors save
modern issues on neatly-trimmed single-layer backing paper.
In 2010, USPS announced
they would no longer increment plate numbers for additional printings of a
stamp, unless there was a significant change in the technology or design.
This is the USPS's definition, not stamp collectors' definition. Since that announcement, most stamps have been issued with plate numbers
of "all ones," and the issuance of additional plate numbers with "all
twos" is unusual and unannounced. At the same time, all other
marginal markings were moved to the back of the self-adhesive pane.
The American Plate Number Single Society was formally
organized in 1976, although it traces its beginnings to 1952. APNSS originally got its start
as an organization for collectors of postally used plate number singles.
APNSS joined the APS as Affiliate #178 in 1988.
39% of our members collect mint (or unused) plate number singles, 27% prefer
used PNS, and the remaining 34% collect both mint and used. [2005
statistics] Stated another way, 73% of our membership collect mint
PNS, and 61% collect used PNS.
Some APNSS members also
collect other marginal markings, such as singles with ZIP, copyright, and pane position
markings, logos, siderographers' or plate finishers' initials, TOP markings, denomination aids
and other markings.
here for a glossary of plate number-related
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This page last updated May 5, 2019.
Opinions expressed by authors are their own and do not necessarily reflect
those of the APNSS, its officers or members.