Portrait of Maria Frederike van Reede-Athlone at Seven Years of Age, Jean-Étienne Liotard, pastel on vellum, 22 x 18 in. (55 x 45 cm), in the collection of the Getty.
18th century Swiss artist Jean-Étienne Liotard gives a beautiful demonstration of the sensitivity and finess possible in pastel.
There is a subtle teture throughout, likely from the nature of the surface, which is natural vellum (a parchment made from calf skin, as contrasted with the modern use of the term to simply indicate a mild texture of paper or board).