Digital BW, The Print

Hello Michael,

>I downloaded QTR...However, I am having trouble getting the 
>deep blacks I got when simply printing through PS CS and the Epson 
>2200 driver. I have played with the sliders in the gui and I have
also 
>tried adjusting the image itself to make sure I have absolute
blacks, 
>but I have not found the answer to the problem. 
>Any help would be greatly appreciated.

The blackest possible print area can only be achieved when there is
100% coverage by only the K ink.  Many systems that blend inks often
mix something else along with the K, even in the lowest zones.  This
effectively reduces the dmax.  I see this with UT7 using sliders,
where it can't match BO dmax.  So you need to adjust the curves to
ensure there is only K down there.  However, I think there is more to
it than just eliminating other inks.

In a BO print the visible paper white specks disappear at around 95%,
yet the Epson driver is still able to achieve gradations between 95
and 100%.  I assume it's because even though the dots are overlapping
at that point, the dot centers are continually spaced closer together
as it approaches 100%.  This means that the amount of ink laid down
increases and affects visual density, even though there is full
coverage of the paper at 95%.

So when adjusting blending curves, seems like the challenge would be
not only when to eliminate other inks, but also how to achieve the 
continuous gradation from that point on with only K ink.

As to where to cut out the other inks, seems to me that any dilution
of pure K is going to weaken the visual affect, so eliminate other
inks at the earliest possible place.  Since the grainy look of a BO
print fully disappears around 80 or 85%, that should be the ideal
place. That would equal BO's dmax and beautiful intensity in the lower
zones, one of its strong points, yet still have a non-grainy print -
the best of both worlds.  This of course assumes the ability to get
the pure K gradation like the Epson driver does.

I would be very interested to hear from QTR/IJC users if this is
possible.  Is anyone doing this?

Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm