Black and Grey Realism
Initially popularized in the southern California prison system (of all places) this style was codified and gained mainstream acceptance due to the efforts of legendary Anaheim-based tattoo artist Jack Rudy. This style lacks line work (or at the very least it is kept rather minimal), and is instead held together with smooth blends of grey shading and contrasting tones, usually garnished in the end with the occasional white highlight to give the piece life. The overall goal makes for a softer, smoother, more realistic look, but one that is inherently time-consuming by nature.