As I have already told you, recently my parents gave me their own collection of postcards, counting 400 more or less postcards!! Most of them are from the '80s and '90s, but there are many that are way older. Unfortunately most of them have no date on them, so I did a lot of reading on how to determine the age of postcards! I will now present you what I have found out. Feel free to comment and tell me more if you have knowledge of the subject!
As I have read, there are several Eras in Postcard manufacturing. Each era has different "marks" such as the color, the frame etc. I guess these eras may different in some countries, but in general they are these listed below:
- Pioneer era [1861-1900]
The most easy way to determine a postcard of this era is to have an undivided back and they usually were printed with a stamp as part of the design, which was included in the price of purchase. Writing was not allowed on the stamp side, except for the address. People often would write around the edge of the card or even on the picture, as there was not much space for correspondence.
- Private Mailing Card Era [1898- 1901]
- Undivided back Era [1907- 1915]
The Post Office was the only establishment allowed to print postcards, and it held its monopoly until May 19, 1898, when Congress passed the Private Mailing Card Act which allowed private publishers and printers to produce postcards. Initially, the United States government prohibited private companies from calling their cards “postcards,” so they were known as “souvenir cards.” These cards had to be labeled "Private Mailing Cards". Although this prohibition was rescinded on December 24, 1901, when private companies could use the word "postcard". Postcards were not allowed to have a divided back and correspondents could only write on the front of the postcard. This was known as the "undivided back" era of postcards. [wikipedia]
- Divided back Era [1915-1930]
The Divided Back period, is also somewhat misleading, since almost all postcards produced since 1907 till present have divided backs. A better term might be Early Divided Back postcards. These cards finally allowed people to write on the stamp side, which is divided into two parts, often marked Address this side and Message can be written on this side or something similar. Now postcard makers could use the entire other side of the card for images, although for a while many cards continued to be printed from earlier printing plates that left white space on picture side to allow for writing. Most of them show a full image, usually with no white boarder.
- White Border Era [1916-1930]
- Linen Era [1930-1945]
The "linen card" era lasted from about 1931 to the early 1950s, when cards were primarily printed on papers with a textured surface similar to linen cloth.
- Photo-chrome Era [1939-present]
The last and current postcard era, which began about 1939, is the "chrome" era, however these types of cards did not begin to dominate until about 1950. The images on these cards are generally based on colored photographs, and are readily identified by the glossy appearance given by the paper's coating.
Many of these categories are not distinct, for example a White Border card can have Undivided or Divided back. This depends on each card, but I guess if you are experienced enough you can determine the age of a card correctly.