Definition & Meaning of "before the ink [is] [dry]"

What is the origin of the idiom "before the ink is dry" and when to use it?

The origin of the idiom "before the ink is dry" can be traced back to the practice of writing with ink and the time it takes for ink to dry on paper or other writing surfaces. The phrase likely originated from the observation that ink takes a short period to dry, and actions or events can occur in that brief span of time. It is commonly employed in discussions or descriptions related to contracts, agreements, or legal documents, highlighting actions taken before the formalities are completed.