To clean black fiberglass tissue, start by using a soft brush to remove any loose dirt or debris. Next, mix a mild detergent with warm water and gently scrub the surface with a soft cloth or sponge. Avoid using harsh chemicals or abrasive materials that could damage the fiberglass. After cleaning, rinse thoroughly with clean water and let it dry naturally. For stubborn stains, consider using a fiberglass-specific cleaner, but always test on a small, inconspicuous area first to ensure it doesn't discolor or damage the material. Regular maintenance will help keep your black fiberglass tissue looking its best.