《EVER-COLORS》have been developed as the reference materials for measuring diffuse reflectance. They have reputation of high and constant reliability and reproducibility in the measurement.K. Ichimura and N. Okazaki confirmed that EVER-WHITE shows an exceedinglyhigh reflectance Included Specular Component Geometry, and that it is exceedingly stable showing no change in reflectance after being exposed for totally 80hrs. to the ultraviolet irradiation of a carbon arc lamp of 135V6A *. Having very high stability of the reflectance. EVER-WHITE, EVER-BLACK and EVER-GRAYS are of essential necessities for spectrophotometers and colorimeters as well as chromaticity measurement. Besides the non-colored series mentioned above, colored series which are very fresh in tint such as EVER-BLUE(Code No.3869), EVER-GREEN(Code No.4808), EVER- YELLOW (Code No.7153) and EVER-RED(Code No.1900)are also available from EVERS CORPORATION. Stability and reliability of all the EVER-COLORS are due to that they are in a solid state. Consequently, their optical surfaces are cleanable to obtain everlasting reproducibility of the measurements. Above all, features of EVER-WHITE(Code No.9582) and EVER-BLACK(Code No.0005) have been included in the report, SURVEY OF REFERENCE MATERIALS FOR TESTING THE PERFORMANCE OF SPECTROPHOTOMETERSAND COLORIMETERS, which was edited and published by C.I.E. (International Commission on Illumination), Division 2, TC-13, in 1985.

*【Reference】 　　K. Ichimura and N. Okazaki : A Comparative Study on Optical Characteristice of Commercial Standard 　　Reference Materials for Whiteness, read at Annual Meeting of Color Science Association of Japan, Kansai 　　Area, March 20, 1981.