PRANG’S STANDARD COLORS, For the Use of Teachers, Designers, Manufacturers, Merchants, and Others who have Need of Standards of Color. These colors have been chosen and arranged in harmonious scales for the assistance of all who need definite and satisfactory standards of color for refer¬ ence, whether in Education, Art, Manufactures, or Trade. They have been fixed upon after repeated conferences with artists and color-experts. Mr. Prang’s work for over fifty years has included large enterprises in the line of color printing, and the reproduction of paintings in oil and water color. Many years ago he began his experiments for definite standards of color, the great need of which has always been felt by those who use color materials in the arts and industries. In the course of his work he came to feel strongly the value of color study as a part of general education, and he continued his experi¬ ments with the definite purpose of producing, in a practical, material form, a series of colors as a basis for color instruction in the schools, and as a standard of reference in the arts and industries. The definition of a scale of standard colors, cover¬ ing, to a practicable extent, the whole physical series of pure color, had Mr. Prang’s first consideration. The only flowing band of color in nature is to be found in the solar spectrum ; but this is incomplete as a physical series of color, and it has not the stability necessary for a proper guide. The varia¬ tions of the colors composing it, in hue, in intensity, in absolute and relative luminosity, influenced by the time of day and by atmospheric conditions, are such that no reliance is to be placed on it for the con¬ struction of harmonious scales of standard normal fi) tones. Nature here, as in all its phenomena, can serve man only as a study for the recognition of the underlying laws : it is his mission to evolve ideals based on these laws. It was recognized by Mr. Prang that the complete physical series of color contained in the wave of white sunlight presents the unit of pure color, and as nature nowhere gives all these colors in combination, the true unit of color has to be imagined. Accordingly, he took for his color-unit an ideal of the colors potentially existing in a wave of white light. A harmonious scale of colors, covering this unit in twenty-four equal inter¬ vals, was then made, not as a mere copy of certain colors of the solar spectrum arbitrarily chosen, but as the result of careful weighing and judging, under the guidance of educated color perception and feeling. The determination of tones for the standard scale of a normal unit color has been derived largely from j artistic and educational considerations, influenced at the same time by the practical requirements and limitations found necessary in the choice of pig¬ ments for coloring. The first stage of work in this color scheme was the painting of models, not only for a series of twenty-four standard normal tones to cover the unit in equal intervals, but also models for all tones in the whole scheme, in order to admit of the judging of the scheme as a whole, and at the same time in all its parts, so as to secure harmonious relations at once between the parts themselves and between the