1969 10s “Royal Court“. A superb unmounted o.g. bottom marginal example of this very rare error of colour with the border printed in green instead of slate blue. A magnificent example of this key Jersey rarity, that occurred when during the final printing one sheet of 25 was accidently fed into the press which had been set up with the green background of the 50p value. Offered with a normal for comparison and a copy of the original letter from the Department of Postal Administration of Jersey regarding how this error occured.