1913, Imperial Russia 300 years of Romanov dynastie, 7 kop orange horizontal pair ECKERLIN ESSAYS printed ca in 1928 on ungummed paper as sample for selling Dr. Eckerlin's rotary press process for intaglio printing (developed by Herbst & Illig in Germany) to postal administrations. In superb condition. A RARE ESSAY. Photocopy of RPS CERTIFICATE (2018) for similar item of same origin included. Similar essay by this company are known for Canada, these are described in an October 2002 articles of the philatelic magazine ”Maple Leaves”: ”Dr. Eckerlin, was director of Herbst & Illig of Frankfurt-am-Main, Germany. In 1928, Dr. Eckerlin contacted Treadway of ABN for purposes of promoting a proprietary rotary intaglio printing process that was faster and cheaper than steel engraved printing.