Imagine the raw, unbridled energy that must have gone into a piece like Jackson Pollock's "Number 12" from 1949. This is where you feel the "action" in "Action painting," a core tenet of Abstract Expressionism. Though the specific medium for this work isn't known, it's clear it emerged from Pollock's revolutionary "drip technique." He wasn't simply brushing; he was pouring and splashing liquid household paint onto a horizontal surface, working the canvas from all angles. This approach gave rise to what's often called "all-over painting," where the entire surface vibrates with activity, lacking a central focal point. It's an extreme form of abstraction, born from what was described as a frenetic dancing style, the artist’s whole body engaged in the act. Critics at the time were famously divided by such immediate creation; some lauded its raw power, while others dismissed its apparent randomness. For "Number 12," the absence of a known medium leaves an intriguing question: does this force us to focus purely on the visual impact of the technique, or does it add another layer of abstract mystery to an already enigmatic work?