The newly dyed red ink stains can be washed with water first, then soaked in warm soapy water, and washed with clear water after the color stains are removed. Red ink stains that have been polluted for a long time should be washed with water first, and then wiped off with 10% alcohol aqueous solution.
2. Removal of blue ink stains
The newly polluted blue ink stains can be scrubbed off with soap, washing powder and other detergents. Blue ink stains that have been polluted for a long time can be soaked in oxalic acid solution and rubbed, and then washed with detergent to remove them.
3. Removal of black ink stains
The newly stained black ink stains can be dipped in hot milk or yogurt. Black ink stains that have been polluted for a long time should be soaked with tap water first, then with slightly hot mixed solution of 3% hydrogen peroxide and 10% oxalic acid, and then washed with water.