Digital BW, The Print

From Hahnemuhle Public Relations:

The Truth About Optical Brighteners in Hahnemuhle Paper
June 4, 2006

There has been growing concern recently about the use of Optical 
Brightening Agents, or OBAs, in digital fine art paper. More and more 
often we hear the question, Are your papers OBA free? The answer is, 
we offer options both with and without OBAs. Because of a 
misunderstanding of OBAs, many people are surprised to hear this 
response. Please let us explain...

OBAs are white or colorless compounds that work by converting 
ultraviolet light into visible light, thereby making the paper appear 
brighter or whiter. They do not change the color of the paper; they 
only fool the eye into seeing a whiter color. After being exposed to 
UV rays for a long period of time, OBAs will begin to lose their 
fluorescent quality, leaving only the natural base color.

There are several methods for adding brighteners to digital media. 
Some companies use the less expensive method of putting OBAs into the 
receptive coating. Because it is not know what effect, if any, spent 
OBAs will have on inks, we add them directly to the paper, ensuring 
that they never come in direct contact with the inks.

Some of our competitors claim that only OBA-free papers meet the 
Library of Congress Standard for Archivability. However, this 
standard refers only to boxes and paper used for storage. A better 
standard by which to measure photographic paper is the Library of 
Congress Standard for Paper Permanence, which does allow the 
inclusion of brighteners. All Hahnemuhle papers meet this standard.

So the claim that OBAs cause paper to yellow or reduce its permanence 
is simply wrong. Eventually, the perceived color of the paper will 
revert to the same base color as papers without; but initially, OBAs 
allow a much brighter base. It is not yet known how long the 
reversion to natural might take. We do know that it is not an 
immediate thing; it could take as many as 50 years (even longer if 
the artist takes measures to protect the image from the effects of UV 
rays.) But the point to remember is that the paper will end up the 
same color as it would have if OBAs were not used.

Consider that virtually all silver halide papers used in darkroom 
photography contained OBAs. Artists who wanted a bright white base 
simply accepted the fact that there would be a slight change over a 
long period of time. In fact, many photographers and collectors find 
this mature look desirable. At Hahnemhle, we strongly feel that to 
provide the paper base color and print color where the artist wants 
it for their lifetime is better than having it wrong from the 
beginning.

Another important benefit of adding OBAs to digital papers is batch 
consistency. By adding OBAs, we can assure that your image remains 
true without having to re-profile every time you purchase paper from 
a different batch.

For more than 400 years the Hahnemhle mill has dedicated itself to 
providing the highest quality paper products. We take great pride in 
the product that we provide our reputation depends on it. While we 
could certainly jump on the anti-OBA bandwagon, we remain steadfast 
in our commitment to the artists choice. Ultimately, we do not cater 
to hype; we cater solely to creativity and quality. We will 
therefore, continue to provide superior media with and without OBAs.