High Quality Content by WIKIPEDIA articles! Denmark issued ten definitive airmail stamps between 1925 and 1934 in two distinct series. The 1st series, commonly called The Plow and Airplane was first issued in June 1925. These stamps were designed by Danish artist Axel Peder Jensen (1885–1972). The 2nd series was issued on June 9, 1934 and depicted an airplane over Copenhagen. The second series remained in use until after World War II.