Great Britain SGDP20(2)c 1840 Rainbow Trial Plate of Twelve
For Sale: £120,000.00
This is a trial plate of 12 from the 1840 Rainbow Trials.
were made to check the printing inks, cancellation inks and an
assortment of papers. Printed in blocks of 12, the stamps were made void
by the removal of a corner (top right) and no corner letters.
trial stamps are printed in black which is the colour finally chosen
for the world's first adhesive postage stamp. They are on thin, white,
wove, unwatermarked paper.
They have 'Prussiate of Potash' in the ink and thus show very strong Ivory heads on the reverse.
A similar sheet is kept in the Royal Philatelic Collection. The Royal Philatelic Collection sheet does not appear to have 'Prussiate' in the ink.
very rare sheet is believed to be the only one currently in private
hands, making this a unique opportunity to own this rare trial plate.
Stanley Gibbons Specialised Catalogue DP20(2)c.