Optical brighteners (OBAs) are chemicals put into certain papers during their manufacture.
These chemicals absorb invisible ultraviolet light and then emit the absorbed invisible light as light our eyes can see, in a process of fluorescence.
When this happens, the white of the paper looks incredibly white, “whiter than white,” because our eyes are seeing a combination of the white of the paper shown by standard light and the light being emitted by the chemical in the paper.
Sounds great, no? There’s just a thing or two to know about this approach…
Risks of Optical Brighteners in Prints
A first challenge is that it’s been difficult to make accurate color profiles for papers with OBAs in them, because most spectrophotometers used to read color on paper were fooled by OBAs causing false readings in part of the spectrum.
While various attempts to correct the problem were made, it’s only recently that new standards and new devices have allowed this problem to be managed more successfully.
Perhaps more challenging, OBAs aren’t permanent, and thus the image won’t look the same over time. What looks great today will dull down eventually, and the permanent image will be less bright than you saw when you first viewed it.
For more on the longevity-associated risks of OBAs, check out this in-depth article.
Is longevity always a problem? Not necessarily.
Uses for OBAs
Why do you think office supply stores can offer you reams of bright white paper at loss leader prices? OBAs make these inexpensive papers look great, and no one expects them to last for the ages.
With prints such as trade show displays, non-permanent installations, prints for evaluation (not for final color, but other tests, such as sizing, retouching and editing, etc) there is rarely an issue with using an OBA-containing paper or canvas, which are often less expensive.
If your print standards require archival permanence, often these papers will not meet archival print standards.
This can vary depending on the level of optical brighteners added to a particular media, though.
Take Breathing Color’s Elegance Velvet or Optica One fine art papers for example. They contain small amounts of OBAs to achieve that extremely bright white, but also meet the Fine Art Trade Guild’s 100+ year archival certification standards.
If you are looking at an OBA-containing media and are also extremely concerned with archivability, I’d recommend investigating whether or not some such archival testing has been performed.
Breathing Color has been a pioneer in OBA-free papers, and the majority of their current offerings are OBA-free. They’re very upfront about which papers are OBA-free, and offer a great selection.
They also provide customers with Archival Quality Certificates which certifies the longevity of their Chromata White Canvas with their Glamour II coating, and the most prominent OEM inks in the industry. This certificate uses 2 different methods and organizations to validate its promise.
If you use the Chromata White Canvas, with the Glamour II coating with Epson, HP, Canon, or Roland aqueous OEM inks, your giclee print is certified archival.
If you don’t use their products, you should demand this type of certification from the manufacturers of the products you are using to make your inkjet prints.
Unless the canvas, laminate, and ink have been tested together and certified, longevity cannot be accurately determined.
And, given that the majority of inkjet canvas and fine art papers on the market have not been print permanence tested, you should assume they are not archival.
You can see in the above photo that OBA-enhanced papers and non-enhanced papers behave very differently under certain illuminations.
The enhanced paper, on the right side, when lit with an ultraviolet light source, is very bright, shouting out its brightness to the world. The non-enhanced substrate is clearly not shouting, quietly sitting there being much the same in ultraviolet and normal light.
I test all my papers with the ultraviolet flashlight you see in the photo to be certain of what I’m using.
The bottom line about Optical Brightening Agents? They make some papers look brighter, and if they meet your requirements, use them.
If fine art or archival prints are needed, OBA-enhanced papers are usually best saved for other uses.
Kevin O’Connor helps design and test software, is a graphic designer and photographer for multiple clients and companies, and fixes people’s (and companies’) color.
He has consulted to multiple companies, including Apple, Sony, Fujifilm USA, and X-Rite. He loves teaching good color practices to enthusiastic learners.
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