Mark Rentschler writes about his methodical painting process: "How to Make a Rainbow is a series of paintings created with methods I use to investigate time in drawing and painting. To produce a visible record of time, I alternate and partially superimpose pencil lines and areas of rainbow-colored paint, experimenting with simple principles including younger-over-older and younger-cuts-older. The physical evidence of earlier time intervals may be obscured by events occurring in later time intervals. Pencil lines are numbered by time interval to document the passage of time and show plainly what I did at each step in the process of creation. My work is concerned with events in my life and the world, and the human desire to investigate and understand."