UNDIVIDED BACK, 1901 to 1907. Cards that have the words Post Card or Postcard on the address side and have no line down the middle to divide the card into address space and message space were used between 1901 and 1907. Such cards often have white space on the front side of the card for a message.
EARLY DIVIDED BACK, 1907 to 1915. The postal service allowed the back of postcards to be divided to allow for a message beginning in 1907. Most cards since then have had divided backs. Early divided back cards printed in Germany or printed without white borders date from 1907 to the beginning of World War I.
WHITE BORDER, Smooth Finish, 1915 to 1930. After 1915, white borders were added to make the postcards look more like photographs.
LINEN FINISH, 1930 to 1944. Beginning in 1930, the fad was to print postcards on paper that was embossed with a linen cloth texture. These cards are often printed in very vivid colors.
CHROME, 1945 to present. The "chrome" printing process was used to produce borderless glossy photographic postcards. Until about 1970, such postcards were the old standard size of 3.5 by 5.5 inches. After 1970, the so-called "continental" postcards were printed in a larger 4 by 6 inch size.
REAL PHOTO, 1901 to present. Real photo cards are actual photographic prints, not pictures reproduced by lithography or offset printing. Real photo cards can be identified by looking at the image under a magnifying glass. If the image is made up of a pattern of tiny dots, it is not a real photographic print.
