Cartor heavy with the ink in Souvenir Sheet?

We now have copies of the London 2010 Festival of Stamps Souvenir Sheet, containing 11 Machin definitives printed by Cartor.  As is to be expected, these show marked differences to the normal sheet stamps printed by De La Rue.  Although Stanley Gibbons' Concise catalogue will probably only assign a number to the whole sheet, specialist catalogues should allocate numbers to individual stamps.

Here are the stamps, Cartor Souvenir Sheet stamps first, followed by the separate DLR stamps:

In fairness I ought to compare the Cartor printings of values they have printed before with their previous versions, but that can come later.  I think the comparison of the 20p & 60p values is most interesting!