30 Pf. brownish olive with net pattern overprint in the horizontal pair, right with side margin, rotary printing, on large sized properly franked printed matter the smelting works Dortmund AG from Dortmund big Barup to Dortmund, very fine, photo expertize study group and expertized Schlegel BPP, Michel - . (side margin pieces 40 % discount on upper margin copies), very rare commercial document!