Digital BW, The Print

I don't think the tags are what trigger the checkbox options.  Its the
data in the LUTs.  If black in the LUT is pure black then you don't get an
Ink Black box -- i.e. blacks are already matched in-to-out, and no BPC needed.
When the black in the LUT is lighter, BPC is default on but Ink Black will turn it
off.   For white I think its slightly different.  White in the LUT is supposed to be
"illuminant white" but the wtpt tag (required) shows the media white.  If these
are different the checkbox Paper White is available.  But this conversion will also
turn off the BPC thus showing Ink Black -IF- it's in the LUT.  Kind of roundabout 
dependencies but the icc spec leaves quite a bit up to the profile designer,
the CMS and the display code (soft-proofing).

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Tyler Boley" <tyler@t...> 
wrote:
>
> I see no consistancy here between the ability to preview paper white
> and/or ink black, and the presence of wtpt and/or bkpt tags in the
> profiles.
> For one odd example, I have 2 profiles here, one will preview paper
> white but not ink black, the other will do the reverse, ink black but
> not paper white. They both have wtpt tags, no bkpt tags.
> This preview ability could also be derived from the LUTs I would
> think. But why some and not others?
> Another unknown. Along with how to make great art.
> T
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Roy Harrington"
> <roy@h...> wrote:
> >
> > 
> > I suspect that this how it works -- that they are linked by the PS code.
> > If anyone finds a counter-example I like to see it.  I don't think
> any of this
> > is documented so examples tend to be the best info.
> > 
> > I think there may be CM systems that don't handle BPC the way PS does.
> > This may be why Epson provides profiles with it builtin.
> > 
> > Roy
> > 
> > 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "John Moody" 
> > <moodymz3@y...> wrote:
> > >
> > > I don't see any profiles that allow simulate paper color without
> simulate
> > > black ink unless they don't have a bkpt tag, so its moot.  Am I
> missing
> > > something?
> > > An interesting example is SPR2400 ProofingSemimatte.icm which does
> not have
> > > a bkpt tag, yet SPR2400 PremSmgls PhotoRPM.icc does.
> > > 
> > > Does that suggest Epson knows most people don't want to simulate
> paper black
> > > while softproofing?  If any profile were to be used for
> softproofing, I
> > > would think ProofingSemimatte would be it.
> > > 
> > > Best regards,
> > > John Moody
> > > 
> > > -----Original Message-----
> > > From: DigitalBlackandWhiteThePrint@yahoogroups.com
> > > [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of
> Steve Kale
> > > Sent: Tuesday, October 25, 2005 11:34 AM
> > > To: DigitalBlackandWhiteThePrint@yahoogroups.com
> > > Subject: Re: [Digital BW] ICC Soft Proofing -- The issue . . .
> > > 
> > > 
> > > Yes but I think the thing we don't understand is why some profiles
> allow
> > > these operations and others don't. That is we need, ideally, to
> figure out
> > > what PS grabs from the ICC profile.
> > >
> >
>