A postcard or post card is a rectangular piece of thick paper or thin cardboard intended for writing and mailing without an envelope and at a lower rate than a  letter. Stamp collectors distinguish between postcards (which require a stamp) and postal cards (which have the postage pre-printed on them).

The study and collecting of postcards is termed deltiology, the German foreign word is Philokartie.

Collecting postcards has become the the 3rd biggest field of collecting passions beside stamps and coins.

Postcards are popular because of the wide range of subjects, with just about every subject imaginable being at some time, portrayed on a postcard.  History itself can be tracked on postcards, from historical buildings, famous people, art, holidays and much more.

Prior to postcards came the lithograph prints, woodcuts and small cards that were the predecessor of the "mailed" postcard.  They were primarily hand delivered. Another direct ancestor seems to be the envelopes printed with pictures on them.

Even 1760 the private City Counsil of Paris (Petite Poste) introduced open messages to the public, a former kind of postcards.

The private postal card was developed by John P. Charlton of Philadelphia in 1861 for which he obtained the copyright. The first "non-Postal" postcard, meaning a privately made postcard where postage had to be affixed was introduced in Austria in 1869 and by 1870, picture postcards were all the rage!

Starting in 1898, American publishers were allowed to print and sell cards bearing the inscription, "Private Mailing Card, Authorized by Act of Congress on May 19, 1898". These private mailing cards were to be posted with one cent stamps (the same rate a government postals) instead of the previous two sent rate. This was perhaps the most important event in making the cards more popular.  Writing was still only allowed on the front side of the card as with government postals and previous pioneer cards.

Around 1900 we saw the first "Real Photo" postcards.  These were postcards that had real photographs and were usually printed on  film stock paper.  Although most "Real Photo" postcards were advertising and tradecards, many were of entertainers and portraits of family members.

Private Mailing Card Era
1898 - December 24, 1901

Sizes

Continental size: 4X6 inches (15 cm X 10.5 cm) Many of the new cards you purchase today are of this size. Mostly published after the 1940's.

Regular (or Standard) size: 3 1/2 X 5 1/2 (9 cm X 14 cm) Many of the older cards are of this size.

Oversized: Anything larger than a continental size.  Mostly 5X7 inches, but some can be found in larger sizes. The advantage is of course the more detailed view of the scenes shown on the cards.

Modern size: These are about 6 1/2 X 4 3/4 inches.  They are often classified as a smaller type of oversized card.

A lot of postcard types have been developped in the past decades. View cards, greeting cards, historical cards, art cards or photographic cards.

The triumphal procession of postcards has changed the world of written messages and became a very popular and successful collector field worldwide.

Postcards have been the best marketing concept for the immortal fame of unforgettable human beings.