Portrait of Gertruida Assink (1602-1679), wife of the mayor of Deventer

Portrait of Gertruida Assink, painted in 1665 when the sitter was sixty-three years old and her husband was serving as mayor of Deventer, exemplifies ter Borch's respectful and psychologically astute approach to elderly female sitters. Gertruida Assink (1602–1679) was a woman of substance and experience, and ter Borch — who knew the Deventer governing class intimately — portrays her with the same observational directness he brought to his portraits of powerful men, making no attempt to flatter her age away. This willingness to portray age honestly, without idealization, is one of the distinguishing qualities of ter Borch's portraiture and contributes to the sense of individual presence that makes his sitters still feel distinctly real nearly four centuries later. This work is held by the Gemäldegalerie Berlin.

Oil on canvas, this late-career portrait is rendered with the assured economy of an artist who had painted hundreds of comparable subjects. The elderly woman's face is modelled through a careful study of its planes and lines, with no attempt to soften age through flattering light or smoothed brushwork. Her costume is handled with precision appropriate to its quality, the dark fabric's texture differentiated through subtle tonal variation.