Castiglione’s pen style changed considerably during the course of his career. As a youth, his sketches (in the first section of the exhibition) were self-consciously vigorous and spiky, strongly influenced by the drawings of the Flemish artist Anthony van Dyck. As he matured, his touch became more nuanced, as seen in the two lyrical landscapes exhibited here. And towards the end of Castiglione’s life his pen lines became ever more spidery, suggesting rather than defining the forms.

Like all his contemporaries, Castiglione used ‘iron gall’ ink, made by adding iron salts to a solution of tannic acid obtained from oak galls. His pen would have been a goose’s wing feather, cut to a fine nib; the flexibility and springiness of the quill allowed Castiglione to achieve a wide variety of effects in his pen drawings.