From the Met's site:
Pastel Portraits: Images of 18th-Century Europe
By 1750, almost 2,500 professional artists and amateurs were working in pastel in Paris alone. Portraits in pastel were commissioned by all ranks of society, but most enthusiastically by the royal family, members of the court, and the wealthy middle classes. Eighteenth-century pastels are brightly colored, highly finished, often of large dimensions, and elaborately framed, evoking oil painting, the medium to which they were invariably compared. The powdery texture of pastel and its diffuse, velvety quality were particularly suited to capturing the fleeting expressions that characterize the most life-like portraits. Pastel Portraits: Images of 18th-Century Europe includes some forty pastels, belonging to the Metropolitan Museum and, with important exceptions, to museums and private collections in the New York area. It presents Italian, French, and English works, supplemented by several German, Swiss, and American examples.Like most fabulous exhibitions, this one will (as of 31 May) have an exhibition catalog. I will have to check out both before these fabulous paperworks are hidden away in the archives!