In sex dolls it refers to the technique of adding spray-painted veins and meridians to the doll’s skin to enhance its realism.

This process involves using specialized paints and airbrushing methods to mimic the appearance of veins, typically applied to areas like the arms, legs, chest, and face where veins are naturally more visible. The result is a more lifelike and detailed appearance, making the skin look more natural and human-like, thus increasing the doll’s aesthetic appeal and authenticity.