10¢ Blue 21UL2
Slight doubling of the top of both numeral boxes, stronger doubling in the bottom line of the right numeral box and in the centre of 'S'.
Research notes:
This image was provided by Leopold Beaudet and is from a plate strip of the dry printing. Plate 21 was used to print both the 10¢ Blue and the 10¢ Bistre and the same re-entry is found on a 10¢ Bistre.
