Saint Peter and a Donor; Saint Thomas (reverse)

Jacob Cornelisz van Oostsanen painted these saints with donor and reverse around 1522 for the Art Institute of Chicago. The double-sided wing panels served as altarpiece components, displaying different saint images when opened and closed. Saint panels were fundamental units of Renaissance altarpiece production, produced individually or as wings of polyptychs, and served the devotional needs of the commissioning church, guild, or confraternity whose patron saint they depicted.

The panels show Jacob Cornelisz's mature technique with careful differentiation of saints through attributes and the warm palette characteristic of his late workshop style.