AluWhite98's aluminum oxide based material exhibits reflectance in excess of 98% over the visible-NIR range. AluWhite98 is available in both matte and gloss surface finishes. All standards are available with NIST/NRC traceable calibrations for 8°/hemispherical reflectance factor from 250 nm to 2500 nm.
The matte material Aluwhite98(m) is quite diffuse and has a slightly higher overall reflectance than the glossy version, AluWhite98(g). AluWhite98(g) is a better choice if the standard needs to be easily cleanable.
Both of these materials should be considered as a replacement for Russian Opal glass, which is no longer available.