This design had to work on multiple colors of t-shirts and had a limitation of 6 colors, so i used the index method of creating the seps. It’s sort of like simulated process but in a lot of ways it is better. Difficult colors like dark turquoise, tans, and browns (like in this design) are not created with halftoned mixtures of saturated color, which can sometimes be sloppy and unpredictable. So you use premixed colors matching the prevalent colors in the design. The trick is picking the right combination of colors and values to make the design look good.