Great Britain Queen Elizabeth II 1966 4d Birds (Ordinary paper), SG696ab.
A superb unmounted original gum left hand marginal block of four with black, blue, bistre and reddish brown omitted, offered with normal block for comparison.
The error results in the loss of value and inscription on all stamps. Also affected are the gull's head, wing detail and water shading; the blue tit's feather detail and branch shading; the robin's wings and legs; and the blackbird's body and legs. The error existed in a cylinder block of eight but was split into two blocks of four in the late 90's.
A wonderful example of undoubtedly the most spectacular Queen Elizabeth II error.