1849-1850 Ceres Issue
20 centimes bleu sur jaune tête-bêche

 tête-bêche, position 148, in unused block of ten, plate 1, positions 136-150

Provenance:
ex Ferrary (sale #11, lot 27 - as sheet of 150), ex Champion and Leuillet

References: 
Ceres #T8, Yvert #8c
illustrated in 2000 Yvert & Tellier Specialisé catalog

Census of blue on yellowish unused:
one block of ten, this is the largest reported multiple in any shade
one block of nine
one pair

Production information:
The twenty centimes blue was to have replaced the twenty centimes black but was not issued. A total of 23.3 million were printed from five plates, including the first plate used for the black stamps, which contained tête-bêche clichés at positions 92, 110 and 148. Although about 100 thousand of the error pairs were printed, virtually all were destroyed by the Post Office in July 1851. Examples survive in all three of the major shades (blue on yellowish, blue on bluish and dark blue).