Of optical brightener
Of optical brightener
- Subject: Of optical brightener
- From: Henrik Holmegaard <email@hidden>
- Date: Sat, 1 Sep 2001 22:39:57 +0200
Simply taking UV filtered and non-filtered readings can detect paper
whiteners and other UV based fluorescence ...
Fiddlesticks, just read the -b channel in the paper measurement using
any old spectrophotometer. If the value is negative, you have optical
brightener. If the value is very negative, like -5 and beyond, don't
write a cheque for that paper, but write it off. Entirely, completely
and absolutely -:).
a. good quality inkjet papers don't have optical brighener,
b. good offset printing papers don't have optical brightener,
c. standards-based ISO and TROO1 simulation profiles don't have
optical brightener (ProfileMaker TROO1 profiles on
www.profilecentral.com and www.eci.org, or profiles you build from
these published data sets yourself the way Adobe did with the bundled
profiles for Pshop 6 ...).
You get optical brightener in poor quality inkjet papers, and in any
quality color copier papers. You want neither in any case.
You don't want to use papers with optical brighteners any more than
you want to use uncoated papers in your inkjet. I posted an Inkjet
profiling ABC in January explaining that inkjet inks are designed to
penetrate the coating unlike lithographic inks which are designed to
be layered on top of each other for maximum production speed.
Therefore, an inkjet gamut is highly dependent on the paper. Sure you
can print on uncoated papers on inkjets, but you wind up with a gamut
shrunk to the size of newsprint or thereabouts, and why on earth
would anybody want that? Which by the way is noted already in the
BESTColor manual version 3.
Set up each printing system to the best of its reproduction
capability and with the widest gamut paper and ink combination you
can find, create a profile for that state of the printer, and leave
your ICC workflow to handle the color space conversions.
Finding good paper and ink combinations belongs with optimizing your
most important in-house color space, that of your studio printer.
Consider what happens if you load an inkjet paper with optical
brightener, How will you tell the difference between a proof of a
simulation space whose page white exhibits optical brightener and a
presentation art print of your own that exhibits optical brightener?
Kill the optical brightener in your in-house printer space, and you
know where the problem lies. Meaning it doesn't lie with you, and you
are not responsible for it, except maybe for knocking on a door and
telling somebody to fix the simulation and final output profiles they
are publishing.