What is the main characteristic of ink used in process color printing?

The main characteristic of ink used in process color printing is that it is comprised of four specific colors: cyan, magenta, yellow, and black, often referred to as CMYK. This color model is fundamental to the printing process because it allows for the reproduction of a wide range of colors by layering these four inks in varying amounts. Each of these colors contributes to the overall color produced on the printed medium, enabling printers to achieve diverse hues and tonal variations. By using this method, designers can create detailed and vibrant images that mimic the full spectrum of colors. The use of CMYK inks is a cornerstone of modern printing techniques, ensuring consistency and fidelity in color reproduction across different printing jobs and materials.