The Tiffen 6.6 x 6.6" Softnet White 3 Filter is a softening filter meant to replicate the look of draping silk over the lens in order to soften or diffuse light. This filter works by scattering light entering the lens through a mesh pattern, resulting in an overall soft glow. The white distinction provides even diffusion and lessening of contrast within the scene. The 3 density provides more softening than the 2, but less than the 4.
Tiffen filters are made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 6.6 x 6.6" / 167.6 x 167.6mm.