The Colorverse Office fountain pen ink series are daily workhorses meant for use at work, classrooms, or just everyday writing. Choose from 7 great standard colors and 3 permanent inks. Each Colorverse Office ink comes in a glass 30ml bottle. Inspired by space and time, Colorverse inks exhort you to colorize your universe. They are carefully blended to conduct the ethereal beauty, wonder, and intense vitality of the universe to your pen. The inks are made with high-purity raw materials and their pH is optimized for a long shelf life.