The Blue Cloak, or De Blauwe Huik, refers to an old concept for a popular 16th-century print series featuring Flemish proverbs.
The prints were generally captioned according to each depicted proverb, and central to these was a woman pulling a cloak over a man.
This act is a metaphor for adultery, explicitly the adultery of the woman, and the cloak a deceitful "coverup" that helps her husband to "not see it", which is also indicated by another proverb or expression in the Galle engraving showing a man with his fingers in front of his eyes with the remark "Dese siet door de vingeren" (English: This one acts blind but is 'peeking through his fingers').
The cloak was called a 'huyck' (huik in modern Dutch), and it was a black garment that was worn by upperclass women when they went outside the home from the 16th century onwards.
This secondary appearance of the huik can also be seen in the Hogenberg and Galle engravings, though it doesn't play a central role.