In the second pane of A Rake's Progress, Tom Rakewell is wearing something that is not a wig on his head. But what is it??
It's bugged me on and off for years that he seems to wearing a - what? A tea-towel, a hairnet? a stocking?
Since this during a morning levée I assume it's a negligé cap. The purpose of this is to cover the head (which was typically shaved) when you did not have a wig.