Chicago Cardboard Company, Chicago, Illinois, manufactures a colored art poster board calendered so that both lettering and printing may be done on it.

REFERENCES

Wallace, C. E., Commercial Art, McGraw-Hill Book Co., Inc., New York City, 2nd edition, 1939.

U. 8. Drpartnicnt of Afirirulturr, Bureau of Agricultural Economic*.

A Series of Density Distinctions.

1. These cross -hatchings were made on sheets of paper by the Bureau of Agricultural

Economics. It is possible for any individual using a great many hachures and desiring a large variety, to design several and have sheets of them printed.

2. To secure the greatest variety in shadings, every fourth or fifth one beginning with

black might be selected.

COLOR AND

Recent years have seen the dawn of a new era in the use of color. An outline of certain color facts and theories may prove helpful.

B.

C.

D.

The above colors arc approximate. The correct hues, vermilion, emerald green, pale cadmium yellow, and light ultramarine blue, may be obtained generally in high grade tempera or show card colors.

A. The Primary Colors as Used and Described by Early Ariists.

Color study was based on human vision alone until Newton made the first physical analysis of liRht about 1672.

B. The Primary Frequencies of Vibration in the Radiant Energy Called Light. Young. 1773-1829; Hclmholtz, 1821-1894; Maxwell, 1831-1899. and Konig, 1832-1901,

proved these three frequencies of light vibration can produce all light colors.

C. The Primary Colors in Pigments as Taught During the 18th and 19th Centuries.