what is the format of postcard????
Answers
You may think that your mailpiece is a "postcard," because it is a single sheet of paper. But to qualify for mailing at the First-Class Mail postcard price, it must be: Rectangular. At least 3-1/2 inches high x 5 inches long x 0.007 inch thick.
Explanation:
Some exposure formats are known as postcard format. These are the following:
Format Aspect ratio Centimetres
Common postcard formats
10×15 cm 3:2 10×15
3¼×5½ inch (122 rollfilm) 22:13 8¼×14
Special postcard formats
2½×3½ inch
(tintype postcard, see Mandel-ette) 7:5 6 1/3×9
These exposure formats are all resembling the common size of postcards or postal cards or were actually used for making postcard photo prints. Postcards became popular since 1875 when the postal card was accepted as international standard for lower rate message sending on un-enveloped rectangular pieces of cardboard, with postal cards mainly w/o picture as kind of prepaid letter, and postcards with image side and writing side. In the early 20th century the format was quite popular as photographic exposure format. Postcards could be made easily from the negatives as contact prints. Special photo paper in thin cardboard quality could be used, with the field for address and stamp on the back.
The Japanese format name Hagaki (Japanese for "postcard") means the 3¼×5½ inch format. In the U.S. the typical postcard format cameras gave the same exposure format and most had the type name extension 3A or No. 3A, regardless of being a plate or a rollfilm camera. The German camera makers preferred the 10×15 centimetres format as postcard format.