Acrylic colour filters are similar to colour glass filters, achieving their colouration by the use of dyes during the manufacturing process. Acrylic filters are cheaper than glass filters, easier to cut to special sizes and shapes but not quite as robust as glass. However, a rather wider range of spectral characteristics is available than with glass.
Two particularly useful types of acrylic colour filters are those which block the visible but pass near IR, and those that pass the visible but block UV light.
Knight Optical supplies a range of acrylic longpass filters available to purchase direct from stock. We also offer a custom service and can cut filters to size specifically for your application. Contact our technical sales team for more information.