Digital BW, The Print

Daniel Staver wrote:

>
>>would it theoretically be possible to develop a GLOP that could increase 
>>the DMAX of matte prints? After all, it's conlusively proven that 
>>various coatings can greatly enhance the DMAX of matte prints, but the 
>>stumbling block seems to be the methods for applying the coating. With 
>>GLOP in a cartridge this is no longer an issue. All we would need is a 
>>coating that could go into a cartridge without clogging the printer.
>>
>>Is something like this possible?
>>    
>>
The only way to get matte prints darker is by using dye inks, with 
pigments you reach a point where the reflectance of the pigment particle 
surface stays equal whatever amount of ink is applied. And that 
reflectance is always higher then with black dye.  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.

Any Glop that increases the Dmax on matte papers will make it less matte 
too. Or that Glop has to have black dye in it and doesn't have to reach 
gloss status ;-)

Generations black has 25% dye in it, it is very black on matte papers 
but will fade in time to its pigment quality.

Maybe we are now at the start of a new rage in adding an extra ink 
channel with black dye that is laid down on top or underneath the 
pigment black in another ink channel :-)
I'm already getting quite close to Generations black on matte papers 
with Eboni so I'm not interested.

There's a new pigment for paints recently developed that has an 
extremely cracked surface, the cracks do something similar as the dyes, 
it is used to get total non reflecting surfaces for optical systems so 
will be used for cameras too. Have you ever seen the walls of 
laboratories that are used for sound experiments, wedge shaped foam 
maybe 30 cm deep sticked to the walls. Small frontal reflection and the 
angle of the wedge so steep that there's no sound reflected from that 
but reflected to the other wedge and so losing its energy till it hits 
the soft wall. That's how you drown sound and light.

An ideal paper coating for inkjet printing should create something 
similar, the ink shouldn't bleed sideways but should bleed inwards to 
create a small well where light can get drown or get filtered deeply by 
the color and return back preferably through that pipe again. Where no 
ink is, the white on the other hand should reflect as much as possible 
directly from the surface. Whether that is possible in one paper coating 
and have an acceptable angle of view is another matter. Gloss paper has  
a bit of that, you loose angle of view in return for more Dmax, the 
white is reflecting more directly, there's a kind of drowning happening 
at the black spots and what is reflected from there is scattered between 
the gloss surface sideways.

Ernst


Ernst