In philatelic terminology a letter sheet, often written lettersheet, is a sheet of paper that can be folded, usually sealed, and mailed without the use of an envelope, or it can also be a similar item of postal stationery issued by a postal authority. Letter sheets derive from the form in which written correspondence was made up before the mid-19th century—letters were written on one or more sheets of paper that were folded and sealed in such a way that the address could be written on the outside.
Opened up 1628 lettersheet showing folds, address and seal, with letter being written on the obverse
A used 1840 hand-coloured 1d Mulready stationery envelope mailed to London
An 1886 2¢ Grant letter sheet uprated by 2¢ and used to Germany, 1888. The letter and flaps were folded for mailing. (Side flaps are still present as they were not torn off upon opening.)
Iraq airmail letter card issued in 1933
Philately is the study of postage stamps and postal history. It also refers to the collection and appreciation of stamps and other philatelic products. While closely associated with stamp collecting and the study of postage, it is possible to be a philatelist without owning any stamps. For instance, the stamps being studied may be very rare or reside only in museums.
The Penny Red was used in the UK for many years (1841–1879), and comes in hundreds of variations which are subject to detailed study by philatelists.
Zeppelin mail from Gibraltar to Rio de Janeiro, Brazil via Berlin on the Christmas flight (12th South American flight) of 1934
1960 Soviet stamp marking Collectors' Day: "Philately serves the friendship of peoples."
A large stamp show (philatelic exhibition) at which collectors and dealers meet
