Translation of "listownik" into English

In philatelic terminology a letter sheet, often written lettersheet, is an item of postal stationery issued by a postal authority; it is a sheet of paper that can be folded, usually sealed (most often with sealing wax in the 18th and 19th centuries), and mailed without the use of an envelope.

In philatelic terminology a letter sheet, often written lettersheet, is an item of postal stationery issued by a postal authority; it is a sheet of paper that can be folded, usually sealed (most often with sealing wax in the 18th and 19th centuries), and mailed without the use of an envelope.