Technical aspects of Otto Dix's <i>Portrait of Josef May</i> (1926), owned by the Cleveland Museum of Art, are described. Between 1925 and 1945, Otto Dix used a painting technique in which egg tempera and oil-varnish layers were superimposed. This is similar to the mixed technique published by Max Doerner. The author speculates that Dix began using this mixed technique because of condition problems with an earlier painting <i>The Trench</i>. The pigments in the painting were analyzed; the resulting information diverges somewhat from Dix's written descriptions. The literature on Dix's technique is summarized and several German sources are translated. Illustrations include: reflectograms, x-radiograph, specular light photograph and details. An accompanying article by William Robinson deals with the art historical aspects of the painting. -- AATA