The assignment for this grid was to use two matched pairs of pigment, one cool and one warm in tone, next to one another, with six colors in four intensities from light to deep in one direction and six colors in the other direction. Across the top, the three matched pairs are, left to right, rose madder and winsor red, burnt sienna and cadmium orange, and yellow ochre and cadmium yellow pale; down, the three matched pairs are, top to bottom, sap green and winsor green, cerulean blue and deep cobalt blue, and winsor violet and thioindigo violet. You never see the individual pigment standing alone; one shade is always crossing another. In order to obtain this chart, I had to lay on masking tape to assure a straight line and mix a small amount of pigment with a large amount of water, layering color on each of the four shade strips, starting with one and ending with up to nine coatings of diluted pigment. The effect, which is not actually totally accurate in the photograph of the grid as reproduced here, is one of a shimmering luminosity. My teacher was Richard Yarde at the University of Massachusetts, and the grid, which I consider one of the most amazing things I ever made, is dedicated to him. The entire work is painted on Arches watercolor paper, 22 x 30 with an additional strip attached to make the final block of color strips. The grid is composed of one-inch squares.