Optical brighteners are additives used by paper manufacturers to make a paper look whiter and brighter.

To make a paper look whiter, it is important to add substances to the paper that shift the invisible ultraviolet spectrum between 320 and 400 nanometers into the visible range from 400 nanometers. This makes the paper bluer or fluoresces in areas that are just visible to the human eye. While our eyes perceive this as a brighter, bluish white, a colorimeter only sees a different blue. Thus, the colour measurements are slightly falsified by the optical brighteners, the created profiles could be yellowish, as the measuring device tries to correct the blueness of the paper.

Many “high white” papers have optical brighteners in them. Partially, the brightening effect weakens over a relatively short period of several years, thus the wisdom of the paper decreases.

OBA is the abbreviation for “Optical Brightning Agents” or optical brighteners.

Optical brighteners are additives that are used by paper manufacturers to make a paper look white and luminous.

To make a paper look white, it is important to add substances that shift the invisible ultraviolet spectrum between 320 and 400 nanometers into the visible range from 400 nanometers onwards. The paper is thereby bluish or fluoresces in areas that are just visible to the human eye so that our eyes perceive that as a brighter, bluish white. Color measurements are so easily corrupted by optical brighteners, for example, created profiles could be yellowish, because the meter is trying to correct the blue cast of the paper.

Many “white” papers have optical brighteners in it. Sometimes, the brightening effect will weaken over a relatively short period of several years, as the whiteness of the paper will vanish over time.