This striking 12-Heller red stamp was issued by Austria in 1910 as part of the grand 80th Birthday Jubilee series honoring Emperor Franz II (as Holy Roman Emperor) / Franz I (as Emperor of Austria). Designed by the celebrated Secession artist Koloman Moser and engraved by F. Schirnböck, the issue is admired for its refined Art-Nouveau ornamental frame and intense vertical-line portrait engraving. The 12-Heller denomination served everyday postal needs and is a cornerstone of the highly collectible 1908–1910 imperial portrait series. Crisp impressions with full margins, like your example, are sought after for exhibiting the precision of Austrian engraving at the height of the empire.