Digital BW, The Print

Daniel Staver wrote:

> >
> >>would it theoretically be possible to develop a GLOP that could increase
> >>the DMAX of matte prints? ...

The water-based coatings did this by making them glossy.  But, of course, we
lost the matte surface.  

Of interest, however, is that the dmax of these originally matte black inks
became very high.  As is also shown by the gloss loss with MIS PK on glossy
paper, as the gloss decreases, so does the dmax.  Then when they are
sprayed, the dmax returns.  

So, at least one major factor in dmax is simply how the light is reflected.
The total reflectance may be the same.  The angles at which the light is
reflected and where the viewer is makes the difference.  With a glossy
surface if one looks at the narrow angle of where that light is reflected,
the dmax is terrible.  With matte paper, that light is reflected evenly
everywhere, this lowers the dmax evenly regardless of which direction the
light is coming from.

Ernst wrote:

> ... Black dye gets more
> Dmax because it doesn't reflect the light as even the black ink has
> transparency and the light penetrates the paper deeper and deeper while
> it is still surrounded by black dye, it is then only reflected when
> white paper is reached.  Scattered and what is left of the light it has
> to return to the surface again following the same path through the black
> dye.

That's an interesting observation.  I had not considered the transparency
factor.  Some to consider the main difference between pigments and dyes to
be the transparency of the final colorant.  However, in my reading on water
color pigments, it appears that transparency is an independent variable that
is also a characteristic of some pigments.  So, while carbon is rather
opaque, other pigments have varying degrees of transparency.

Perhaps this explains how the cyan or blue pigments with relatively low
density actually increase the dmax of the carbon black inks.  If this is the
case, then what we may want is the darkest pigment over coating that has
high transparency.  Consistent with this, phthalocyanine (probably cyan
pigment) has relatively high transparency.



> I'm already getting quite close to Generations black on matte papers
> with Eboni so I'm not interested.

I agree.  Have you tried a dark cyan overcoat?



> 
> There's a new pigment for paints recently developed that has an
> extremely cracked surface, the cracks do something similar as the dyes,...

But wouldn't the cracks also let oxygen in and cause the fading to be
faster?


Paul
www.PaulRoark.com