breaking lead
Expression referring to an instructor's frustration (literally: mechanical pencil lead breaking under excessive comment writing pressure) while marking a student paper which violates both instruction and Standard American English.
After having marked 42 essays that compared and contrasted two poems, nearly every one of them ignoring the pointed lesson of the previous class, by the 43rd I was breaking lead when the student wrote that the poets had "concocted imagery" and employed "religious illusions".
Break a Lead
A wish of good luck offered to a writer. The term is to Break a Leg which is offered to an Actor. Break a Lead is rumored to stem from the ancient practice of breaking a piece of lead into a small chard suitable for writing.
"Break a Lead", the editor said to his reporter as he sat down to write his cover story.