A systematic gradient chart displays two vertical columns of color scales transitioning from deep black through jewel-toned purples, magentas, and pinks on the left, to earthy olive-greens, golds, and pale yellows on the right. This nineteenth-century scientific illustration exemplifies the methodical study of color relationships, rendered with precise horizontal bands that shift incrementally in tone and saturation across the composition. Printed on smooth white card stock and made to order, artwork on the front, blank inside, envelopes included in every set. A handwritten note that arrives as an independent artist's work.