1917, 20¢ Light Ultramarine, Imperf Between, vertical pair, o.g., lightly hinged, typical centering, strong color, nearly Fine, attractive example of the very rare 1917 20¢ Washington imperforate vertically between variety, with many certified examples bearing faults or natural s.e.; with 2013 P.F. certificate. Scott No. 515b  $4,000 for the grade of fine. $0 (Image)