Nauru #85 $1 Magenta Map of Nauru, 1968 Overprinted Decimal Definitive Issue, a VF NH Lower Left Inscription Block of 4
A well centered and very fine NH lower left inscription block of 4 of the $1 magenta map of Nauru stamp from the 1968 overprinted decimal definitive issue, printed on Helecon paper, as noted below.
These stamps were printed by the Reserve Bank of Australia and thus will mirror Australian issues of the period, in terms of the varieties that exist. Most of the engraved stamps are found on dull paper, but starting in 1965, many of the Australian issues can be found on fluorescent paper. The photogravure issues are usually all fluorescent from the front, but on the back the fluorescence ranges from dull to hibrite.
The Australian equivalent of tagging is called Helecon, which is a chemical in the zinc sulphide group that fluoresces orange-red under long-wave UV light. The very first stamp to be issued with Helecon coating applied to the paper was the 11d Rabbit Bandicoot from the 1958-1964 definitive issue. Later, the 5d orange-red Queen Elizabeth II stamp from the 1963-1966 issue was issued with the Helecon incorporated into the ink. By the end of 1965 all stamps issued had Helecon applied to the paper. On this issue, most stamps are found with the paper coated with Helecon, so that they glow a dull orange-red.
Scott lists four singles at $11 for VFNH. However, the inscription block should be worth at least a modest premium. The block offered here grades 80 as follows:
Paper freshness: 5/5
Absence of visible paper flaws: 5/5