Greek vases often show thick matt brushstrokes usually white, yellow or purple in color on the thin black varnish and the red ceramic beckground. A chemical study of such brushstrokes revealed presence of beeswax and fatty acids, suggesting they were painted with water-soluble encaustic *.
Attic black-figure amphora painted by Psiax. 510-505 BC. Museo di Santa Giulia, Brescia. White and purple encaustic applied cold on black varnish and red ceramic.
* José Cuní y Jorge Cuní. Naturaleza de los colores fugitivos en la cerámica griega. Archivo Español de Arqueología, 63, 1992, 34-35.