The V&A says: This costume comes from Meleto Castle in Tuscany, where there is a private theatre, which was opened in 1741. It is a very early example of a costume made specially for the stage and, although probably used in productions of plays, it was also undoubtedly used for masques and other entertainments which included dancing. Furnishing velvet rather than finger velvet was used as it was more effective in candlelight and because it would better withstand the weight of the metallic embroidery. The use of such precious metals and expensive fabrics was only within the means of rich artistocrats.

(Source: ornamentedbeing, via miss-mary-quite-contrary)