A postcard may be a cardboard that is thin and it has mailing or writing and does not need to be placed in a envelop and the shape may actually vary but there are exceptions are made of wood and thin wood and there are some which are made of copper.
The post cards are usually printed by companies which are private or by organizations and individuals and the post card are provided by postal authorities which are commonly owned by government.
The first appearance of postcards that had pictures on them allows and encourages many people to send numerous images to countries which are far away and many countries allow the postcards to be mailed to individuals and the images may be those of the countries famous tourist sites.
In many countries there is no permission of post cards which have images of nudity or sexual references and even images of partial nudity and classical paintings and statuary and there are many types of postcards which include the applique postcards which is made of some metal or cloth and other embellishments which are attached to them.
There is art deco postcards which has straight lines and symmetrical designs art nouveau which has characters of flowery symbols and flowing lines which depicts some impressions of representation of art and there is artists signed postcards which have artwork of an artist’s signature and the art is unique and there is bas relief postcards which have surfaces which are raised and this gives an appearance of papier mache.
There are intermediate size postcards which have standard sizes and there are kaleidoscopes which have a wheel that rotates and reveals colors that are myriad when the card is turned and there is the large letter postcards that have series of some large letters and a picture while the midget postcards and novelty postcards which deviates in some ways from the normal ones and the cards have articles that are attached to them and they are usually printed in some unusual sizes and have material that are strange and they may be even made or leather.
There are other cards such as standard size postcards, the topographical postcards which have photo postcards of broad streets and the undivided back postcards have plain back with a space for writing the address and there is the vignette post cards which consists of a design that has a whole picture on one side but has space on which to write a message on the other side and the write-away postcards have an opening sentence written on it and the sentence is not complete and one needs to complete it.