Private masquerades were by invitation, of course. Public masquerades, however, were very popular throughout the eighteenth century. Entrance to these public masquerades, often known as subscription masquerades, was obtained through the purchase of subscription tickets [1]. Tickets could be purchased from coffee houses, or from the venue itself [2]. They were also advertised for in journals and newspapers. Ticket prices were lower in the early part of the eighteenth century, but steadily rose [3].

Endnotes

1. Castle, Terry. Masquerade and Civilization: the Carnivalesque in Eighteenth-Century English
     Culture and Fiction
. Stanford, CA: Stanford University Press, 1986, 10.
2. Castle, 29.
3. Castle, 10.