Switzerland 1979 ATM (Frama stamps)
Type 3 Helvetia small, lilac, paper with fibres,
single value on letter cancelled during duration period "08.08.1979 8023 Zürich 23 Hauptbahnhof", luxury quality,
SBK 3, ZST 3, Michel 3.1a, Seitz 3, Schalch 3.
Explanations: Duration: 12.01.1979-25.11.1981, cliché: HELVETIA (small), type of digits: narrow, printing color: lilac, paper: with fibres, glossy gum, fluorescent: no surface (phosphorescent), impression cylinder: imprecisely moletted, white-greenish-blue security underprint (rosettes), color ribbon: silk ribbon II, printing: Wertzeichendruckerei PTT, Bern.