The X-ray film technique in filmmaking involves creating visuals that resemble X-ray images, providing a skeletal or ghostly effect. This technique is used to add an eerie or otherworldly aesthetic to the footage, often to emphasize themes related to the internal, hidden, or the macabre. It requires special post-production effects or animation to simulate the appearance of X-ray imaging, as actual X-ray radiation is harmful and not used in standard film production.