Switzerland, Winterthur - 1850 2 ½rp, glass support cliché of background with reversed image, showing what is red in the original stamp, with notation "cuivre sans verni" (unvarnished copper) and indication about the light "B.L." over the screen which was used for the two minutes and thirty seconds exposure, “2'30"". (Image)

Switzerland, Winterthur - 1850 2½rp, glass support cliché in negative, displaying what is the red part of the design in the original stamp, a unique production from the Sperati workshop exemplifying one important component for manufacturing this famous Swiss cantonal. (Image)

Switzerland, Winterthur - 1850 postmark, a composite glass support cliché for the P.P. postmark, in grey brown and with reversed image; featuring two prints of the postmark of which one is outlined by the stamp to indicate positioning, annotated “dépoli au papier verre usé" (frosted with sandpaper used). (Image)