Quote:
Gibbons doesn't say so in so many words, but this must have a two-plate printing. With the 1910 6c red, Gibbons says 'Printed from a single plate.' so by inference, the earlier low values weren't.
Ah I see now that Scott also lists the 1910 6c carmine (33a Scott) as from a single plate. So two plates it is.

Most likely the flaw is a transient.
Thanks tonymacg.
