A Twenty Four sheet is a size of poster that is approximately 
      24 times the size of the one sheet. This statement alone would seem to be 
      a very simple and easy to understand explanation.... HOWEVER... it's not 
      quite that simple.
    The world's first 24 Sheet was displayed at the Paris Exposition 
      of 1889 by Morgan 
      Litho. This gained them worldwide attention and established Morgan as 
      a major lithographer in the industry. 
    In the US the 24 sheet normally 
      measures 108"x246", and is used for billboard advertising, although 
      in older days some were placed on the sides of large buildings and barns. 
      They come in a number of pieces and are placed together like a puzzle. Their 
      artwork is designed to catch the attention of motorists as they drive by. 
      They are issued primarily for major motion pictures. 
    Because they are made of paper stock and glued onto the 
      billboard, few survive from having to tear them off to replace them with 
      the newer piece. 
    For more on this size see the US article on Twenty 
      Four Sheet. 
    In the UK, however a twenty 
      four sheet is a COMPLETELY different size AND can get quite confusing. The 
      explanation would STILL be the same.. that it is approximately 24 times 
      the size of the one sheet... BUT it then depends on what you determine the 
      one sheet to be. What we call a 24 sheet, the British film industry calls 
      a 48 sheet.
    For more information on this size, see our UK article on 
      the 48 Sheet