Pair
1. Two of a kind; stamps that have not been separated, two attached stamps.
2. Two se-tenant postage stamps; understood to be se-tenant horizontally
Pane
stamps as sold by the post office; usually a commemorative pane consists of 50 stamps; four panes of 50 stamps make up a "sheet" of stamps as printed; more recently panes consist of 20 stamps.
page of booklet postage stamps. [see Booklet Pane]
Perf
abbreviation for Perforation [see Perforation]
Perforated
[see Perforation]
Perforated Edges
The number of sides of a stamp that have perforations. see Perforation (Perf).
Often a coil stamp has 2 opposite sides of the stamp perforated and the other 2 sides are not. A single stamp from a booklet may have 2 adjacent sides perforated and the other 2 sides are not perforated, or onlty one side not perforated. [see
Perforation]
Perforation
Holes punched, in a line, into the stamp paper between rows of stamps to permit easy separation of the stamps. (abbreviation Perf) Perforations are measured by counting the number of peaks or valleys in the perforating in any given 2cm space.
A 11 x 13 has 11 perforations in 2cm on the top (or bottom) and 13 on either side. A single number measure means that the perforation count is the same on all sides.
A 10 verticle means that both left and right are perforated 10 and the top and bottom are not perforated. 10 horizontal means that the top and bottom perforations are perfed 10 and the left and right are not perforated at all. These last 2 are usually coil stamps, issued in long stripes or coils, one stamp wide, so for seperating the stamps, only 2 sides need to be perforated.
Perforations are usually measured using a perforation gauge. [see Perforation Gauge]
Perforation Gauge
An instrument designed to measure the number of peaks or valleys in the perforating in any given 2cm space. Perforations are usually measured using a perforation gauge. Paper perforation gauges have rows of dots or a sawtooth arrangement where you line up the teeth of perforations of your stamp with the row of dots and read off the perforation count. Clear plastic perforation gauges is also available. With it you can lay the gauge on the stamp (useful if it is on a cover). It also has slanted verticle lines on the plastic, when the perforations on the stamp line up with the lines, then you read the perforation count off of the gauge. It also has the advantage of being able to measure fractional perforations, like a 13.2 .
Phosphor
A chemical printed on stamps in order to help automated machines process the mail by reacting to the phosphor under ultraviolet lights. It started in Great Britain in 1959, and many countries now use a phosphor "tagging" on their stamps.
Plate Block
(abbreviation PB) A block of stamps with the sheet margin attached showing the plate number used in printing that sheet. Usually collected as a block of four stamps or more.
Plate Number
1. The serial number engraved on a plate which usually appears in a corner of a sheet of stamps. This number is used to keep the plates from getting mixed up at the printing plant.
2. Single digit suffix numbers are printed on the coils, instead of the whole serial number.
Postmark
(abbreviation Pm, or Pmk) Any mark cancelling the stamp and recording an item's passage through the mails.
Proof
A trial printing, known as a strike, taken from a new printing plate for inspection purposes; this can be used to inspect for defects, or to see which ink color looks best for that particular stamp.
Provisional
A stamp, usually overprinted or surcharged, issued for temporary use.
