Dive into a world of endless possibilities as the fountain pen ink metamorphoses from tranquil blue to passionate pink, or from sunshine red to mysterious yellow. Explore nine beautiful colors awaiting to showcase their hidden secret: Fuchsia/Yellow, Blue/Neon Yellow, Deep Blue/Pink, Brown/Green, Black/Green, Burgundy/Orange, Red/Yellow, Green/Pink, Purple/Yellow. The colors are accompanied by the Monteverde Ink Color Changer Solution. Traditionally exclusive to color changing markers, this innovative colorless liquid has been meticulously formulated to meet the exacting standards of fountain pen enthusiasts and therefore is completely fountain pen safe! Seamlessly integrating with any ink from the Color Changing Ink collection, the Monteverde Ink Color Changer Solution enables effortless color transitions like never before. Whether you choose to fill your fountain pen with the Monteverde Ink Color Changer Solution or employ a brush or dip pen, prepare to be captivated as the ink undergoes a breathtaking metamorphosis, revealing a palette of stunning hues before your very eyes Made with Monteverde's European Ink Treatment Formula (ITF), it ensures smooth flow, extended cap-off time, and protects your pen's ink feeding system. Compatible with a wide range of fountain pens, it guarantees an effortless writing experience for writers, doodlers, and pen enthusiasts alike. Unleash the magic, add enchantment to your writing, and make every stroke a work of art with the new Monteverde Color Changing Ink Collection. (Note: The Monteverde Color Changing Ink Collection is not responsible for any sudden bursts of creativity, spontaneous poetry, or uncontrollable whimsy that may occur while using our product. Enjoy responsibly!)