To clean black fiberglass tissue, follow these steps: First, use a soft brush to remove any loose dirt or debris. Avoid using abrasive materials that could scratch the surface. Next, mix a solution of mild detergent with warm water. Dampen a soft cloth or sponge in the solution and gently wipe the fiberglass tissue. Rinse the area with clean water to remove the detergent, and then dry it thoroughly with a clean, soft cloth to prevent water spots. For stubborn stains, consider using a fiberglass-specific cleaner, but always test on a small, inconspicuous area first to ensure it doesn't discolor the material. Regular cleaning will help maintain the appearance and longevity of the black fiberglass tissue.