Laminated glass can crack and separate.
Resin and plastic can easily scratch. This thin, metallic film results in a spectral density curve that is relatively flat within a spectral range between 380 nm and 760 nm. Because of this neutrality, the overall appearance is a colorless, gray tone. All ND filters are manufactured for matched filter sets. Adhesion of the alloy film to its optical surface is tenacious and unaffected by moisture throughout a reasonable temperature range.