1928: ECKERLIN ESSAY for Romania 1928 King Michael issue ”GROSSHERZOG MICHAEL VERSUCHS-MARKE”, pair in vermilion with SPECTACULAR PLATE FLAW IN THE FACE OF PRINCE MICHAEL on the left stamp. These essays were used as samples for selling Dr. Eckerlin's rotary press process for intaglio printing (developed by Herbst & Illig in Germany) to the Romanian Post. PROBABLY THE ONLY EXAMPLE KNOWN WITH THIS PLATE FLAW. Michael I (25 October 1921 to 5 December 2017) was the last King of Romania and 7 years old at the time of these essays.