Digital BW, The Print

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...
>>>
>>