Portrait of Gisbert Cuper (1644-1716)

Portrait of Gisbert Cuper, painted in 1675 on copper and depicting a sitter who was thirty-one years old at the time, is one of ter Borch's rare surviving works executed on a copper support — a material associated with miniaturist precision and extraordinary surface smoothness. Gisbert Cuper (1644–1716) was a Dutch humanist scholar, classical archaeologist, and later member of the Académie des Inscriptions et Belles-Lettres in Paris, representing the learned, internationally connected intellectual class that occasionally patronized ter Borch alongside his more typical merchant and civic clients. The choice of copper as a support suggests this was a prestige commission of a particularly intimate kind — copper portraits were often small in scale, highly finished, and intended for private contemplation rather than public display. Museum De Waag in Deventer holds this work, making it a fitting example of ter Borch's enduring connection to the city where he spent the latter half of his life.

Oil on copper, this portrait achieves an extraordinary surface refinement impossible on canvas or panel. The metal support's non-absorbent surface allows paint to sit with exceptional smoothness and enables extremely fine detail in rendering both the face and the costume. Colors remain vivid and transparent, with copper's warm reflectance contributing a subtle glow to the overall tonality.