Postal Card, 1891, 1¢ blue on grayish white, Double Impression (in blue and black), One Inverted. Mint card with normal impression in blue, with a second impression inverted, vert. crease, Fine, quite likely either a trial proof or printer's waste, nonetheless a highly collectible and visually striking piece. UPSS No. S12dP. Scott No. UX11bP  Estimate $200 - 300. $0 (Image)