The best way to node a metallic 3D model is using a PBR (Physically Based Rendering) workflow with separate nodes for base color, metallic, roughness, and sometimes specular—this accurately simulates how real metal interacts with light.
Base color adds subtle tints (like copper’s red). The metallic node defines metal areas (1 = fully metal, 0 = non-metal). Roughness controls reflectivity sharpness (low for polished chrome, high for scratched steel).
For beginners, use pre-built PBR templates in tools like Blender or Substance Painter—start with defaults, then tweak roughness to match your metal type (e.g., higher roughness for brushed steel vs. chrome).