There is so much gold and bronze trim on models that it's nuts. Getting good shade in the details and even just painting the larger areas with metallics is hard as they cover thinly. This is where this ink comes in.
Liberally apply it, apply extra in the shadowy areas, let it dry, and then go over with those coats of metallics to get crisp, vibrant, darker yellow in cracks and crevices gold and yellows!