Digital BW, The Print

"Sylvain M." <sylvain@...> wrote:
>
>... I usually consider a tone as neutral when Lab B is 
> between 0 and 2. Am I right?
> 

As a practical matter, I think think that is correct.  Of course, dead neutral would be Lab A and B = 0.  However, a one unit difference is barely perceptible.

Actually, I think viewing conditions are huge factor.  I have Arches watercolor paper prints on the wall that look very neutral.  In fact, however, the paper base is creamy warm (about Lab B = 3), as is the natural paper mat board.  The image tone (Eboni-6) peaks out at about 2.5 units above that.  Yet, because the eye appears to do a "white balance" on the Arches paper and mat board, the prints look neutral.  The image tone, being about 2.5 Lab B units warmer, if we look at the differential between the nearby paper white and maximum image warmth, is close to your estimate of 2 as what people will see as "neutral."  Most viewers, seeing the prints without another reference, simple consider then B&W prints -- no obvious tone at all.

The mistake many people seem to make is to view their prints and test strips next to their 6500k monitors or next to very bright typing paper.  In comparison the prints with even slight warmth look "brown."  If those are the conditions that one expects the prints to be viewed in, by all means, use paper with lots of OBAs and inks that are almost half color pigments.  For that type of print, I even prefer the Claria/Noritsu dyes on bright, high gloss paper.  

The point is, lighting and display conditions make a big difference.  When I was hanging shows that were a mix of neutral silver-gelatin and inkjet prints, I tried to use inks that would match the silver print tones.  While I still keep a silver print hanging in my office for reference, as long as the prints are not side-by-side, no one sees any difference between the silver and Arches/carbon prints.  (Actually, I do.  The carbon on Arches are usually better.)

Paul
www.PaulRoark.com