10 pfennigs Berlin cash medium sienna and 12 pfennigs Berlin cash red, imperforated proof print the country printing office Berlin with 10 pfennigs on the front- and 12 pfennigs on the back, on ungummed greenish white cardboard paper without watermark, slightly oblique extending creases, unsigned, photo expertize STROEH BPP (2010) "otherwise is the proof print perfect. me are so far first seven examples this trial proofs are known. ", Michel 1800.-