Scott paints a gesture of a Southwest Butte to demonstrate finding a tone that will establish a framework for future painting.
The Tate Museum defines tone as "the relative lightness or darkness of a color". Their definition goes on to say that "One color can have an almost infinite number of tones". No wonder Scott says tone is a difficult concept to understand.
In difficult areas of painting , one of the simplest things you can do is a series of gestures to find your way.
When Scott starts a painting, he attempts to find a relative lightness / darkness that will unify the colors on a plane.
To develop a tonal study:
Find at least three subjects with significantly different tones. For example:
For each subject, develop one or more tonal studies as described in Key Takeaways.
Journal your observations.
Oil or gouache colors.