Optical brightening agents or OBA’s make paper more ‘white’ in appearance and increase the overall brightness of the paper. Brighteners remove the off-white or sometimes yellow appearance of raw materials within the paper. Some controversy exists within the photographic community with respect to the use of brighteners and their archival longevity. It should be noted that most traditional photographic materials contain(ed) brightening agents and were widely accepted. It is only recently that their use has been frowned upon.

All OBA's will fluoresce under UV illumination (black light) and are fugitive by nature.