BASIC BLUE 9 - Methylene Blue - C.I. No.52015 - CAS No. 61-73-4 Methylene Blue, Methylene Blue 2B, Basic Lake Blue BB, Basic Blue BOC, Basic Blue 4RF, Basic Blue BO, Methylene Violet. Application area: Paper, Textile, Detergent, Marking Ink, Writing Ink, Dry colors, Agricultural Spray Marker Dye, Plastic. The powder is widely used in industries. We make available our powder in safe packaging of the best quantities. Moreover, we make available our product at the most affordable price. The minimum order quantity of the product is 100kg. We make sure to deliver the orders well on time at the required destination.