Cartor DP 459 5p
the quality and precision of images is clear
lithographic - heidelberg press
anomolies of IS overlay exist also in decimal values - and not only NVI group. most appear from Walsall press production, however in time I imagine some delarue may surface also. cartor machins - so far unknown
my study of 1st and 2nd class, has shown that besides migration of the iridescent overlay ; missing letters and degraded areas appear ... again, the walsall press at fault ... certainly the overlay screen is subject to wear and tear.