The stamps feature a ‘dream team’ of legendary footballers selected from around the United Kingdom namely Jimmy Greaves, John Charles, Gordon Banks, George Best, John Barnes, Kevin Keegan, Denis Law, Bobby Moore, Bryan Robson, Dave MacKay, and Bobby Charlton.
Royal Mail worked very closely with the National Football Museum and with its experts, archivists and curators, to establish a listing of the key great footballers to celebrate. The football museum itself has established a Hall of Fame and the players selected were from those who were inducted into the Hall of Fame when it began.
Royal Mail also looked at the history of UK football, but applied criteria to select players whose key senior career was within the years 1963-1990s, who will be much more familiar to present day footballers than those of earlier eras, and include many players who have a cult following and widespread agreement of genius on the pitch, such as George Best.
The stamps are 30 x 32mm and the miniature sheet is 192 x 74 mm.
There will also be a prestige stamp book (details to follow) and a series of retail stamp books, the first of which contains 4 x 1st class red Machin definitives and the football stamps showing George Best and Bobby Moore.
A second retail booklet will be issued later in the year* with the John Charles and Dave Mackay stamps. * The issue date will be subject to operational need and may be in 2014.
The England badge on the selvedge for the Bobby Moore stamp in the retail booklet is very poor - it's hanging off the shirt! (Click on the image below for a yet larger one.)
Update 13 May:
John E has reminded me that I haven't posted details of the cylinder numbers on this booklet, so here is the image of a cylinder booklet.
All W1, the 'colours' are dark red, phosphor, iridescent, magenta, cyan, yellow, black - although the iridescent and phosphor are difficult to distinguish.
Update 1 June Phosphor shifts:
Colour mis-registration on this issue is less obviously wrong, but the alignment of the phosphor patches on the cylinder is most irregular.
We have many booklets with the phosphor on the Bobby Moore stamp only dropped by up to 2mm. Other booklets have a downward shift of the phosphor on all 6 stamps, while some booklets have phosphor short on all except the George Best stamp! Oddly all the booklets with cylinder numbers have accurately placed phosphor.
With two booklets this will also mean
Update 12 March
We now have images of the PSB panes. The more I look at it, the more I think this issue is a good idea gone bad. The two definitive panes have been badly designed, as to their contents and layout. Pane 1 should have had the national stamps in the corners, or at N,S,E & W. Pane 4 has values so low (total 34p) that they should require extra stamps for a FDC!
Update 28 April
We now have the actual PSB panes, and I am disappointed to say that the two Football Heroes stamp panes are self-adhesive. Disappointed (a) because no data on this was provided by Royal Mail in the pre-release publicity, and (b) because this means that collectors will feel they have to buy twice as many of the footballer stamps as they thought they would!
The definitive panes are gummed, with security codes M13L MPIL on all the Machins and no security printing on the country definitives.
According to the credits in the book, the booklet is printed by Cartor Security Print. But a second paragraph states that the definitive panes are in gravure by Walsall, which they are not.
I've also worked out why the price of this pane is odd - the whole booklet price is £11.11
Special postmarks for this issue are shown on our website.
For the specialist collector this stamp issue rivals Dr Who in its complexity and the number of stamps. There are 34 individual stamps, a miniature sheet, retail booklet and PSB. The individual stamps are:
Footballers - 11 gummed, 11 self-adhesive from PSB by Cartor, 2 self-adhesive from retail booklet by Walsall. (Total 24)
Country definitives - 4. The three flags stamps have never had individual catalogue numbers before. The gummed Northern Ireland stamp has been printed in litho before but not by Cartor. There are also other differences, see below. 
Machin definitives - 1st class self-adhesive with MCIL M13L code (the MCIL London Underground stamp has the M12L year code), 1st class gummed, 1p, 2p, 5p, 10p, gummed all with MPIL M13L codes. 
The new Northern Ireland stamp by Cartor, as well as being yellower than the earlier one, has no microprinted date in the figure of value: