Leather stored in damp or humid conditions may develop mold or mildew. Mold appears green or black and slimy, while mildew is white, grey, or yellow, with a fluffy, powdery texture. To tackle these issues, wear a face mask and gloves for protection & clean the leather with a damp cloth soaked in a vinegar solution to remove mold, allowing it to air dry. Prevent mold by storing your jacket in dry conditions with proper air circulation—avoid plastic wrapping.