Page:Atlas of the Munsell color system.djvu/11

 CHART

CHART V. AXIS of the color tree.

(A scale of neutral values 0—10.)

VALUE, i.e. the amount of light reflected from pigments, is the second dimension or quality of color,—the other two being HUE and CHROMA.

A Scale of natural or gray values tends from the extreme of whiteness (10) to the extreme of blackness (0), and is represented on this chart by the hinged and perforated card. The value of any color is readily found by sliding it behind these perforations until a point is reached where the luminosity of the color matches that of a step in the gray scale. Should the value fall between two of these steps, the interval may be given decimally.

Thus the yellow has a value of eight (8), green is five (5), red and blue four (4), purple three (3). Personal bias plays no part in this measured scale of value. It is established by a special instrument adopted in the course of optical measurements, at the Mass. Institute of Technology, and known as the Munsell Photometer.

These pigment colors vary not only in their VALUE, but also in their CHROMA,—as fully shown on Chart C, which explains why the color branches extending outward from the neutral axis are of uneven length. See chapters II and III of the teacher’s handbook, "A COLOR NOTATION," (second edition).

PROTECT THE CHART FROM DUST AND HANDLING.