Extreme Radiator Black Paint SEMI GLOSS Finish is formulated to advance heat exchange with minimal build up. Engine and multi-purpose paints can restrict airflow and cooling effectiveness by clogging up radiator fins and preventing air flow. Frost Extreme Radiator Black is a durable coating that will withstand temperatures up to 150°C. Semi-gloss paints have a slightly glossy appearance and are less reflective than gloss paints.