It is typically off-white in color, relatively odorless, and stays pliable for an extended period of time.
Rope caulk has also been applied to the metallic structure supporting the magnet for a dynamic speaker to cut unwanted resonance of the metal structure, leading to improved speaker performance.
It has also been used as a sonic damping material in sensitive phonograph components.
Mortell Co. of Kankakee, Illinois in the 1940s, and called "pliable plastic tape".
Its primary ingredient is titanium dioxide; it has a specific gravity of 1.34.