Great Britain 1860 1d red-brown Plate 10, SG16varA Perkins Bacon perforation trials exhibition showpiece of the utmost rarity Great Britain 1860 1d red brown Plate 10, (Perkins Bacon perforation trial), SG16var. A superb unused, with original gum, right hand marginal block of ten lettered 'BH CL'. The Perkins Bacon perforation trials used the balance of a sheet of the imperforate 1d red brown, Plate 10, left over from the creation of postal notices in 1841. These were used by printers, Perkins Bacon