According to Stanley Gibbons:
"Graphite lines
Vertical black lines printed on the back of certain British stamps in 1957. The substance used was called Naphthadag (Deflocculated Acheson's Graphite) and was employed in connection with early experiments at Southampton with the automatic sorting of mail. Stamps intended for use on fully paid mail, such as sealed letters (and later the second class rate), had only one line. This permitted the segregation of mail into the basic categories for sorting and stamping. These lines were superseded by phosphor bands."
My questions...since these were only used in 1957, how rare are they? While sorting through all my GB stamps, I've only seen one so far (out of about 500). Anyone else have any of these?
Posted 01/14/2013 10:52 am
