The sixth regular issue is a repetition of the fifth on paper with a vertical watermark. The designs are the same as those of the third issue, with the same size. Background of alternating Arabic and Roman numerals "2". Two-color printing. White, lightly surfaced paper with horizontal laid lines. Watermark: wavy lines. Perforation 14½:15.
From 1868, parts of the print runs of the 6th issue were printed with the ribbing lines on the stamps oriented vertically (vertical "laid") in order to use the paper more efficiently when cutting it into printing sheets.