Helpful Info on U.S. Plate Block Stamps
US plate block stamps are a key part of the stamp production process. The number in the selvage refers to the plate used in printing the stamp sheet. They’re fun to collect because owning one is like owning a piece of US history – the history of the stamp’s creation. They’re also great for display. Some people like to collect single and plate block stamps of the same Scott number to put in their album side by side. US plate blocks are found in lower quantities than single stamps or even pairs and are becoming harder to get as time goes on. Read on to learn more about them…
1894 2¢ Washington Type II (US #251) Plate Block
Flat Plate Printing – These US plate blocks are typically collected in blocks of 6 (sometimes 4) stamps with the plate number centered within the selvage. The plate block can come from the top, bottom, left, or right of the sheet depending on how the stamps were printed. Most US stamps printed from 1847 to the 1920s were created using flat plate printing.
1938 1 ½¢ Martha Washington (US #805) Plate Block
Rotary Printing – These US plate blocks are typically collected in blocks of four. The plate block appears in one of the four corners of the sheet: upper left, upper right, lower left, or lower right. Rotary press stamps were printed in continuous rolls and cut into sheets of four panes (most collectors call these panes “sheets”). Each of the four panes has a plate block in a different corner. US stamps printed from the 1920s to 1970s were created using rotary printing.
1987 25¢ Bicentenary Statehood: North Carolina (US #2347) Plate Block
Photogravure Printing – These US plate blocks are typically collected in blocks of twice the number of stamps as number of different colors on the stamp. For example, a stamp printed in three colors used three plates, each with a different plate number. This means the plate block would contain six stamps. A stamp printed in six colors would have a plate block of 12 stamps.
The plate numbers appear in one of the four corners of the stamp sheet: upper left, upper right, lower left, lower right. Photogravure stamps were printed in continuous rolls and cut into sheets containing four panes (most collectors call these panes “sheets”). Each of the four panes has a plate block in a different corner. US stamps printed from the 1970s to 1990s were created using photogravure printing.
2000 33¢ Black Heritage: Patricia Roberts Harris (US #3371) Plate Block
Modern Lithographed/Photogravure Printing – These US plate blocks are typically collected in blocks of four (sometimes more for se-tenants of more than four designs). Each stamp issued uses plate #1 for the first printing and #2 for the second printing. The single digit allows several numbers (each representing one printing plate for a different color) to fit on one stamp.
Modern lithographed/photogravure stamps were printed in continuous rolls and cut into sheets of four, six, nine, or ten (possibly more) panes (most collectors call these panes “sheets”). Each of the four panes has a plate block in a different corner: upper left, upper right, lower left, or lower right. Multicolored US stamps printed from 1995 to present were created using modern lithography/photogravure printing.