When the plaster hardens and is removed, I'll get a mold of his cowl. Not only that, but Batman would be permanently plastered.
11 seconds sound clip from Batman (1966) - The Thirteenth Hat (S1E13) TV Series.
You can hear this line at 00:23:14 in the Blu-ray version of the movie.
Quote context
[...]
- Cappy, Dicer, what are you waiting for?
- I prepared myself with my anti-mesmerizing Bat-reflector.
- What did you do that for, boss? Now you'll never get his cowl.
- Oh, it's a far, far simpler end for the cowled crusader.
- Oh, it's a stroke of genius on my part if I do say so myself.
- And I'll be killing two birds with one stone. Two birds with one stone.
- How does Batman get out of this plaster trap?
[...]