Ludwig von Siegen
... that the printmaking technique of mezzotint was invented in 1642 by professional soldier Lieutenant-Colonel Ludwig von Siegen? 
... that the <a href="./Printmaking" id="mwCf8" rel="mw:WikiLink" title="Printmaking">printmaking</a> technique of <a href="./Mezzotint" id="mwCgA" rel="mw:WikiLink" title="Mezzotint">mezzotint</a> was invented in 1642 by professional soldier Lieutenant-Colonel <b id="mwCgE"><a href="./Ludwig_von_Siegen" id="mwCgI" rel="mw:WikiLink" title="Ludwig von Siegen">Ludwig von Siegen</a></b>? <i id="mwCgM">(example mezzotint pictured)</i>