Poland 1951 – Souvenir Sheet, National PZF Philatelic Congress Warsaw – 6-Year Plan Propaganda Stamps – Used

Original Polish souvenir sheet issued on the occasion of the National Congress of the Polish Philatelic Union (Ogólnokrajowy Zjazd Polskiego Związku Filatelistów), Warsaw 1951. The sheet bears four stamps from the «Naprzód do walki o Plan 6-letni!» (Forward to the Fight for the 6-Year Plan!) series, a defining example of Polish Socialist Realist stamp design of the early 1950s.

The four stamps — 45gr, 75gr, 1.15zł and 1.20zł denominations — depict a male and female worker in heroic poses, representing the industrial and social aspirations of the Six-Year Plan (1950–1955). The sheet header bears the patriotic slogan: «Wspólnym wysiłkiem całego narodu zbudujemy Polskę Socjalistyczną» (Together, by the effort of the whole nation, we shall build Socialist Poland).

Catalogue references: Fischer Bl.7 / Michel Bl.9. Condition: used, with clear cancellations; sheet has light age yellowing consistent with its period, structurally sound with no tears or major faults. A striking piece of mid-century Polish philatelic and social history.