For many decades traditional photo papers have been covered with OBAs – so-called optical brightening agents. Why? Because consumers expected “whiter than white” prints. But here is why you should think twice if you care for your environmental footprint.  

What are OBAs?

Present in most laundry detergents and many papers, textiles, paints, plastics and cosmetics, OBAs are chemically based, fluorescent dyes added by paper manufacturers to enhance paper whiteness and brightness. These chemicals absolve invisible ultraviolet energy and re-emit a portion of this energy as visible light in the blue wavelength region of the spectrum. Because our eyes are perceiving both the white of the paper and the light being emitted by the chemicals, we see a super blueish white paper.

So where is the problem?

There are actually several problems: environment, longevity and colour profiling.

Environment

OBAs are not biodegradable. They leach toxic chemicals into the soil and water, harming fish and animals. They may bioaccumulate - stick together to form sludge in high concentration. As a result, they pose a potential hazard to aquatic life and may even cause mutations in bacterial cells adding to the problem of resistant bacteria.

Longevity

Apart from environmental concerns, OBA-free fine art prints are much more print stable. As dyes, OBAs are more prone to fading than pigments as they lose fluorescence with time. So if you want future generations to see an exactly as bright image as you saw it when purchased, avoid papers with OBAs. Of course, this varies depending on the number of optical brighteners added to the paper as well as on the amount of exposure of your print to UV light.

OBAs in Giclée FineArt prints 

It is especially important to check the number of OBAs in Giclée FineArt prints. Due to aqueous pigment inks used on high-quality fine art papers, they are museum-grade prints with the high archival performance so longevity is crucial factor to them.

Colour profiling

While a human eye sees a paper with OBAs as a brighter, blueish white, a spectrophotometer used to read colour on paper only sees this as a different form of blue. As a result, the profile is trying to correct for what it identifies as a large amount of blue in the paper. So fine art prints on paper with a lot of OBAs can end up being with a yellow tint added to them. Colour profiling inaccuracies might add a particular challenge for artists when building ICC colour profiles.

Conclusion

For environmental reasons, try to opt for OBA-free papers or with a very low amount of OBAs. This is not so easy as most papers do contain them but do not necessarily list their inclusion on the packaging. But environmentally conscious fine art paper producers like Hahnemühle or Canson always attach detailed technical information on each of their papers, which is also downloadable as a PDF on a paper description page.

When you purchase Giclée FineArt prints, OBAs should be avoided where possible. If not OBA-free, opt for Giclée prints on fine art papers with a very low amount of OBAs. Request this information from an artist or gallery, if it is not stated explicitly.

For instance, the French paper company Canson explicitly marks all their OBA-free fine art papers in their catalogue of papers with the phrase "no optical brighteners". The French paper company substitutes OBAs with some natural pigments. 

What else can you do?

What else can you do apart from buying OBA-free fine art prints? For instance, don't buy laundry detergents with optical brighteners. Instead, opt for the many non-chlorine oxygen-based bleaches on the market.

Other Names for OBAs

You may identify OBAs among product ingredients also through the following synonyms: Optical Whiteners, Fluorescent Brightening Agents, Fluorescent Brighteners, Fluorescent Optical Brighteners, Fluorescent Whitening Agents (FWAs), Fluorescent White Dyes, and Organic Fluorescent Dyes.

Photograph: by Freepik