Embossing from 1970 to 1981
[dal 1953 al 1969]  [dal 1982 al 2000]  [dal 2001 al 2005]  [dal 2006 al 2008]  [dal 2009 al 2018]
"NOTICE: this list is no longer updated, as this type of stamp is no longer considered to be unusual due to the number issued."
1970 - Sierra Leone
1970 - Jugoslavia
1970 - Saint Lucia
1970 - URSS  
1971 - Germania Est
1971 - Finlandia
1971 - Tonga
1972 - Nazioni Unite - Ginevra
1972 - Nazioni Unite - New York
1972 - URSS
1973 - Finlandia
1973 - Hong Kong  
1973 - Tonga
1974 - Finlandia
1974 - Germania
1975 - Canada    
1975 - Libia
1976 - Canada  
1976 - Venezuela
1977 - Canada
1977 - Francia
31-10-1977 - URSS
02-11-1977 - URSS
1977 - Polinesia Francese
07-10-1978 - URSS
1979 - Germania
1979 - Is. Gilbert / St. Helena / Solomone / Sud Georgia      
1979 - Togo
1980 - Benin
1980 - Germania
1980 - Canada
1981 - Giappone
1981 - Togo      
1981 (1982?) - URSS
"NOTICE: this list is no longer updated, as this type of stamp is no longer considered to be unusual due to the number issued."