> -----Original Message-----
> From: sandersm@... [mailto:sandersm@...]
> Sent: Saturday, August 23, 2003 8:08 PM
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: [Digital BW] Moab Entrada: To Brighten or Not To Brighten?
>
>
> Antonios Ricos writes:
>
> "the Entrada is 100% cotton, acid free and that the Natural
> contains no optical brighteners"
>
> I was asleep for the discussions about optical brighteners. Can someone
> explain to me the case against them, apart from aesthetic
> preference, if any, as
> they are used in a paper like Entrada? I appreciate that this is one of
> those questions that has probably been beaten to death on this
> list, so an offlist
> reply would be fine, if someone will indulge me.
Sanders,
Optical brighteners or optical brightening agents (OBA) commonly added to
paper or the coating on the paper are chemicals that fluoresce. When
ultraviolet light strikes the brightening chemical the chemical emits a
small amount of light in addition to the visible light the paper reflects.
If you look at these papers with a UV or black light you can see the
difference.
The plus here is that this makes the paper brighter and increases the tonal
range by lowering the minimum reflective density. The down side is that
ability of the chemicals to fluoresce is finite and after a enough exposure
to UV light their ability to fluoresce will be lost. This leaves the white
portion of the print duller than it was when you originally made the print.
In addition most OBA become faintly yellow when they are exhausted. When
this degradation will occur depends completely upon how the print is
displayed and how much UV exposure it experiences.
Difficult to know in advance how the prints will look when this has happened
as the amount and quality of the chemicals used will effect the final
result. If you are curious take one of your prints on the paper you ordered
and place it on the deck of your car's rear window where it can bake in the
sun for a couple of months. This should give you a worse case example.
I generally prefer papers with brighteners and haven't used any non-OBA
papers in quite awhile. With quality papers and proper display conditions
papers with brighteners should hold up just fine. Use the paper that appeals
to you the most or suits your work.
It should be noted that fine silver fiber papers use OBA's in the coating
layer between the gelatin and the paper. For some reason no one seems to be
greatly concerned with these papers but OBA's have become an issue with
inkjet papers.
There is some more info on OBA's in the files section of the group homepage
in folder:
Files > Archival Issues
>
> Acting entirely on faith, I was the third buyer to place an order for the
> Septone package for the 2200. The nice lady at
> inkjetgoodies.com swears they
> are shipping on Monday. I bought some of the Entrada with
> brighteners (geez,
> just like laundry soap!) to go with it. How stupid was that?
I have sample prints from R9 printed on a 2200 and on a 7600. I think they
are excellent. The other variable toning solutions tend to shift the hue of
the print across the entire tonal range. With the Septone system you can
independently control the hue of the shadows, mid tones and high lights
separately if you want. I think this has the potential to produce a much
richer and more subtle print.
I hope that you will report back to us on your experience with the inks and
software.
Martin Wesley
http://www.borderless-photos.de/guests.html