Spain: 1851 2 reales blue, error of colour.
Printer: Government Printing Works, Madrid
Medium: Surface printed
The second issue of postage stamps for Spain appeared in 1851, with six values of similar design, including the 2 reales in red, and 6 reales in blue.
The 2 reales error of colour was caused by the accidental insertion of a 2 reales cliché in the printing plate of the 6 reales. This was then printed in blue giving the error.
Only three copies of the stamp are recorded to have survived and this one was the first to be found. It was subjected to a test for genuineness sometimes made in the nineteenth Century – it was boiled. This treatment removed almost all of the postmark of which only a smudge remains today.