This is a Royal Mail A4 Poster as displayed in Post Offices to promote new stamp issues in this case The 1989 Industrial Archaeology GB Commemorative Museum Year Stamps, Ironbridge Shropshire, Tin Mines St Agnes Cornwall, Mills New Lanark Strathclyde and Pontcysyllte Aqueduct Clwyd, Reference number PL(P)3650 5/89 CG(E) issue date 4th July 1989.