How do I know if my black fiberglass tissues are clean or dirty after use?

To determine if your black fiberglass tissues are clean or dirty after use, check for visible signs of dirt, dust, or residue. Clean tissues should appear free from any visible contaminants. If there's any doubt, it's best to assume they are dirty. Additionally, consider the context in which they were used; if they were in contact with a dirty or contaminated environment, they are likely dirty. Regular cleaning and inspection are crucial to maintain hygiene and functionality.