Penny Red plate numbers are important. The rarest plate to be used is number 77, from which it is believed that only one sheet of stamps was printed.
According to Post Office records, printing plate 77 – which dates from 1863 – was rejected due to poor alignment which meant that some stamps were mis perforated in production.
Although the only sheet printed by plate 77 was meant to be destroyed, a few examples have been unearthed by collectors during the last century.
The most recent example to be sold from this plate fetched £495,000 when it was successfully auctioned in March 2016 – making it the UK’s second most valuable stamp.
Bought by unnamed British collector, the Guardian newspaper reported that this rare Plate 77 Penny Red (pictured below) is one of only five used examples known to philatelists, but there are more likely 10 -12 perhaps.
For stamp collectors and investors, Plate 77 Penny Reds are the holy grail of philately because they were not meant to exist.