Rohrer & Fountain Pen Cleaner Klingner 45ml This product is specifically designed to remove any ink residue that may have remained on fountain pens. Some water-resistant inks like SketchInk contain binders that can leave more residue on your pen than regular non-water-resistant inks. Recommendations for cleaning feathers:  - Fill the fountain pen with the cleaner. - Let it soak for 5 minutes and rinse it with plenty of water. If necessary, repeat and extend the exposure time. Contains 45 ml. Brand: Rohrer & Klingner.