I have always been facinated by masquerade and theatre costumes. So for your amusement, a collection of 17th century dito.
Woman Holding a Mask and a Pomegranate by Lorenzi Lippo
Unknown woman in a masque costume by Oliver Isaac, ca 1609
Lady Elizabeth Pope by Robert Peake the Elder (1551–1619)
Henrietta Maria, Princess Palatine, third daughter of Elizabeth of Bohemia, by studio of Gerard van Honthorst
Sophia, Princess Palatine, fourth daughter of Elizabeth of Bohemia, dressed as an Indian, by her sister Louise
Elizabeth, Princess Palatine, eldest daughter of Elizabeth of Bohemia, by studio of Gerard van Honthorst
A Lady in Masquerade Costume by , John Michael Wright, ca 1679
Abraham Willaerts Cornelis Tromp i Roman costume, by Abraham Evertsz. van Westerveld, 1673
Emperor Leopold I in theatre costume by Jan Thomas, 1667
Mademoiselle Subligny Dansant a l’Opera, 1688-1709
Inigo Jones was not only an architect, he designed stage desig, costumes and masques as well.
Elizabeth Manners, Countess of Rutland, costume designed by Inigo Jones, 1606 by John Decritz the Elder
Lucy Harrington, Countess of Bedford, costume designed by Inigo Jones, 1606 by John Decritz the Elder
Costume design for a lady masquer by Inigo Jones
Costume design by Inigo Jones, 1613
I'm not sure if these really are masquerade clothes, but they sure aren't ordinary ones.
Marie de Rohan, Duchess de Chevreuse, unknown artist
Henriette Adelaide of Savoy, Electress of Bavaria, unknown artist, ca 1670
I know that I have osted these before, but for the sake of keeping everything in the same post, extant masquerade costumes from Livrustkammaren and Skokloster.
Harlequina costume, probably worn by Queen Ulrika Eleonora The Elder, 1656-1693
Mock armour in velvet, linen and chamois leather, ca 1672
Not sure if this really fits in, but it is at least in a similar vein.
Carousel costume in silk and metallic lace, ca 1872
To finish, just plain fashionable ladies wearing masks. Popular to wear when you went out into the dangerous sun, and not worn for a masque.
17th century engraving