Colored-Glass filters are fabricated by blending light-absorbing chemicals into molten glass to define precise spectral signatures. Bandpass, edge, heat absorbing, and neutral density filters can be made using colored glass technology. We offer a wide variety of custom and catalog colored glass filters using Hoya and Schott colored glass. We also offer Colored-Glass Alternative (CGA) Filters for use in applications where a thin-film filtering approach is desired. Long wave pass CGA filters are offered as alternatives to most of our Schott and Hoya long wave pass filters as well as at some cut-on wavelengths that have been discontinued by the colored-glass manufacturers.