Digital BW, The Print

Thanks Carl. I only access this forum via the web interface, not the
emails, and your correction hadn't appeared on the web at the time I
saw your original post. So apologies for any unnecessary hassle.

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
<scho@...> wrote:
>
> I corrected that mistake in a follow up post:
> "Sorry, put in the wrong numbers for x-rite.  Should be L 96.2 a  
> -0.52 b 0.56."
> 
> So yes they are very different in terms of Lab a and b values  
> (particularly the latter).  I think the un-filtered (UV) i1 is really  
> not appropriate to use for assessing color of papers containing OBA.   
> The Match color profiling software corrects for OBAs but most of us  
> have been using MeasureTool for aquiring data when making B&W  
> profiles for QTR and I don't believe MT has the capability to make  
> the UV adjustment.  I see now why ColorBurst recommends (actually  
> requires) the UV filtered hardware solution.
> 
> Carl
> 
> On Apr 7, 2006, at 6:57 AM, alanrew42 wrote:
> 
> > Carl, the two figures you give for the 'b' reading are the same
> > (-4.31) so I'm puzzled about your saying they're different... or have
> > I missed something?
> > TIA
> > Alan
> >
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
> > <scho@> wrote:
> >>
> >> I just measured Innova F Type paper white again using both my i1 (no
> >> UV filter) and a UV filtered x-rite pulse.  I took 4 measurements
> >> with each.  The average i1 reading was L 96.3 a 0.69 b -4.31.  The
> >> average x-rite reading was L 96.2 a 0.69 b -4.31.  The lack of UV
> >> filtration is probably why the i1 gave such a low b value.  The Lab b
> >> value difference also is probably indicative of OBA presence.
> >>
> >> Carl
> >>
> >> On Apr 6, 2006, at 8:09 PM, John Vitollo wrote:
> >>
> >>> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
> >>> <scho@> wrote:
> >>>>
> >>>> Smoother surface than silver rag and it doesn't have the glittery
> >>>> reflections that silver rag has (or at least what I saw in the
> >>>> beta).  Not as warm as the silver rag paper ,but not really a  
> >>>> "blue"
> >>>> white either.  Here are some lab data for the Innova F Type paper
> >>>> white: L  96.03	a 0.70	b -4.20
> >>>
> >>> Silver Rag LAB values from production roll:
> >>>
> >>>                L 96.10     a 0.81       b 1.13
> >>>
> >>> I just started building Silver Rag B+W profiles for InkJetControl
> >>> and have not printed an image
> >>> yet so no paper evaluation at this time...
> >>>
> >>
>