4c Columbian (233). Mint
N.H., bright color and proof-like impression on bright fresh paper,
Extremely Fine Gem, with 1991 P.F. certificate for block of four (Image)
4c Columbian, Error of Color
(233a). Variety with third leaf in oval surrounding right "4", original
gum, lightly hinged, the more intense of the two error shades, fresh and
bright paperVERY FINE AND BRILLIANT EXAMPLE OF THE RARE 4-CENT COLUMBIAN ERROR OF COLOR. ONE OF THE FEW KNOWN WITH THE "THIRD LEAF" VARIETY.
The 4c Columbian color error was caused by the use of a wrong batch of ink. Spectrographic analysis proves that the ink of the 4c error matches that used for the 1c.
With 1979 P.F. certificate (Image)