Optical brighteners - and their fading

[The Hat]

@Ink stained Fingers, why don’t you test the O/B paper first, on your next exposure test hang an unprinted O/B sheet out with your test samples and after your allotted prescribed time bring it back in doors.

Now print an image on the exposed O/B paper, and then print the same image on a new O/B sheet straight out of the box, then hang both images out together, time will tell something...

 

[Ink stained Fingers]

I did a simple test and placed an unprinted sheet of Netbit paper out into the sun, together with the DL ink patches.
Most of the optical brighteners in this paper are gone after 2 weeks as viewed under UV light

The paper is clipped into a poster rail at the bottom, this stripe is unexposed and lighter with the OB's still active.
The OB's are vanishing very fast, even faster in the cheaper coast coated papers, this raises the overall question how and whether they should be considered at all in the profiling process.