Essay_(philately)
In philately, an essay is a design for a proposed stamp submitted to the postal authorities for consideration but not used, or used after alterations have been made.[1][2] By contrast, a proof is a trial printing of an accepted stamp.
Both essays and proofs are rare, as usually just a few are produced. Although intended for internal use by printers and official bodies, essays sometimes find their way onto the philatelic market.
