A 1966 British Birds 4d block of four is among the star error lots currently auctioning at Brandon Stamp Auctions.
The right sheet marginal se-tenant "four colours omitted" error has a catalogue value of £20,000 ($32,244), a testament to the fact that it is "considered by many to be the finest example of a British missing colour error", according to the auction house.
The mint condition, unfolded and extremely fine example is currently auctioning for £4,725 ($7,616), with 11 days of bidding left before the lot ends on December 15.
Specialising in error stamps, the rolling online auction also features a highly rare 1968 Olympic Games 3d, which has omitted the country name and value.
Currently selling for £1,012 ($1,631), the Post Office fresh unmounted mint specimen has a catalogue valuation of £4,750 ($7,658).
A 1981 Falkland Islands Plants 15p Brown Rush error, in the rare light brown colour and lacking the Queen's head, inscription and territory, is auctioning for £1,147 ($1,849) - confirmation of the desirability of this unmounted mint example.
Brandon Stamp Auctions' sister company, Brandon Stamps, is also selling two highly important British Commonwealth imperforate blocks: a 1d Vermilion mint "Woodblock" from the Cape of Good Hope, priced at £300,000 ($483,685), and a mint 1848 1d Orange-vermilion corner sheet marginal block of four, which last changed hands in 1967 for $64,000.
Paul Fraser Collectibles has our own beautiful example from the British Commonwealth, the Black Empress.
For more of the latest from the world of philately, sign up to our free weekly newsletter.