Digital BW, The Print

When preserve numbers is checked, soft proof is simply showing you-

this device/paper/ink will make these particular numbers (tones,
levels, whatever) look like this WITHOUT any conversion.

So it really is a "profile" in the strictest sense, a characterization.
Intent, BPC, etc. are all relevant only when converting, and are user
choices about the method of conversion. We are not using these
profiles for printing, therefore not converting to them. Without
preserver numbers checked, softproof is showing you how your file will
look WITH conversion to the profile, so also allows you to select
those options in the preview. In the normal color world, using device
profiles, these are all relevant issues as you mention.
Paper white and ink black are preview options only, and have nothing
to do with how conversion will take place. Therefore those options are
available whether or not the preserve box is checked. I don't want to
get too lengthy about complicated color management issues here, but
here's a quick barely adequate explanation-
Without paper white or ink black checked, preview matches the white
point of the profile to the white point of the working space to the
white point of the monitor profile, all to their various 100,0,0 LAB
representations. Similarly, black ink does the same at the 0,0,0 LAB
point. So the supposed full scale of the profile is matched to the
supposed full scale of the monitor.
Since any profile includes a "device" black point and white point,
which is really measured paper white and dmax, Photoshop provides the
ability to take advantage and use that info, converting those values
through the various profiles to represent their monitor space
equivalent. It's purely a proofing option and unrelated to other more
common icc related issues.
I get tongue tied just trying to explain, but I hope that helps.
Tyler


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
<stevekale@b...> wrote:
> 
> Hi Tyler 
> 
> I don¹t know whether you have followed the discussion that Roy and I
were
> having about soft proofing (QTR question for Roy) but I was intrigued by
> your comments below.   In the colour world one would choose an
intent and
> check Use Black Point Compensation.  Furthermore one would most properly
> check Simulate Paper White (and, as a result, Ink Black).  Although many
> find the initial effect of doing so quite off-putting it does
actually lead
> to better soft-proofing.  I was wondering what the difference is
when in the
> B&W world we check Preserve Colour Numbers (rather than using a
rendering
> intent).  How does Simulate Ink Black (and I guess one should also check
> Paper White) work in a Preserve Colour Numbers world?  I guess at
the heart
> of this I am wondering why Preserve Color Numbers is used.  Because
we use
> Same as Source at printing?  Can you help me muddle through this?
> 
> Steve
> 
> From: "Tyler Boley" <tyler@t...>
> 
>  I find some very
> critically chosen separations, particularly near 100%, more accurately
> predicted with the icc soft proof profiles, particularly with ink
> black checked.
> Takes a while to get used to the look of it, but ink on paper always
> looks so different than the monitor that I need all the help I can get.
> Those with EyeOne Photo may want to give it a try, it's very easy to
> do. If custom dot gain in PS had some more curve points, or allowed a
> simulated dmax like profiles do, it would surely help.
> Tyler
> 
> 
> 
> 
> [Non-text portions of this message have been removed]