Create a detailed sketch using vibrant, full-colour techniques. This CMYK 4-colour ballpoint pen includes Cyan, Magenta, Yellow & Black. Create every colour by combining the 4 inks. Includes a mixing guide on the packet. The CMYK process is used in printing to create full-colour images. Now, you can use this process to make full-colour art with this ballpoint pen. Change inks with the sliding selectors. Coloured ink tubes in the precise nib provide visual confirmation. Experiment, doodle, sketch, get cross-hatching, and get creative. But most importantly, never leave home without it.