Digital BW, The Print

This patent application has some interesting information on OBAs:

http://www.patentstorm.us/applications/20100230061/description.html 

The materials indicate what types of brighteners are usually used in paper, as opposed to the, supposedly, better ones in textiles, 

This patent application is claiming that there is a way to put the better textile types of OBAs into plastic strips and have them in the paper. 

"[0007]Surprisingly, it has now been found that by treating a pulp suspension with a filler composition comprising finely divided optically brightened plastic fibres, an optically brightened paper of high lightfastness is obtained in an economic manner."

Some background is given first in paragraph's 3 & 5 (quoted further below).  I'm sure there is a lot more out there.  

Given the importance of image stability to what we do, I thing it's a field worth keeping an eye on.  

Test prints using very good inks from Jon Cone and HP had some bad Conservation Display Ratings in the Arrdenburg-Imaging (http://www.aardenburg-imaging.com) fade tests that had nothing to do with the pigments -- carbon sepia and Vivera.  But the OBA burnout triggered the end point on the Conservation Display Rating even thought the pigments were not fading.  That is, the images' overall appearance had changed noticeably -- not good.  The poor papers that did this were Alise BW and HP Pro Satin.  See http://www.aardenburg-imaging.com for the test reports.

Paul
www.PaulRoark.com 

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Some interesting background info in the patent application:

"[0003]Optical brighteners of the triazinylaminostilbene type have been used almost exclusively to brighten paper either by application to pulp or to the paper surface. It is well-known however that the lightfastness of brighteners of this type is no better than poor to moderate, ...


[0005]EP-A-801 700 overcomes some of these problems by describing the use of optically brightened polyacrylonitrile powder to prepare white coating slips for paper. Preferred optical brighteners are those typically used to provide a high lightfastness on textiles, for example of the triazolylcoumarin or benzoxazole type.