Conversation so far:
Why is Marx known for this mustache?
The absurdity of the greasepaint was never discussed on-screen.
Was there a way that he curled his mustache?
CANNOTANSWER.
What about his eyebrows make them notable?
his natural hair eyebrows were too undertoned and did not match the rest of his face, so Marx added the greasepaint to his eyebrows.
Are there any other interesting aspects about this article?
The exaggerated walk, with one hand on the small of his back and his torso bent almost 90 degrees at the waist was a parody of a fad.
did he suffer ill effects from the walk?
CANNOTANSWER.

Question: When did he start using the greasepaint for his brows and mustache?
Self-contained rewrite: When did Marx start using the greasepaint for his brows and mustache?