Wiktionary
blue film
n. a pornographic film
Wikipedia
Blue Film (album)
Blue Film is the debut studio album released by the American singer-songwriter Lo-Fang
Usage examples of "blue film".
They were all high as kites, laughing uproariously and half-watching a blue film on the video, in which a plump redhead was doing unmentionable things to a supine Father Christmas.
And, she wondered, could it be really true that all the mind and love and hope in the universe was confined to that thin blue film of dirt and water and air?
A thin blue film dulled his black eyes, though the haze seemed to cause him no trouble seeing.