Digital BW, The Print

Oh,

I forget to add: As you go down in density of say K and the dots 
become visble at 60% patch desity, the next dense ink has to be able 
to support this density at reasonable ink limit, preferably less than 
80% ink limit.

I hope this does not make my logic even more murky.

With this in mind, and judging based ONLY on ramps, I may want to 
revise my recommendation to a higher number of ink shades than 3.

Shilesh

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Shilesh Jani" 
<shileshjani@...> wrote:
>
> Daniela,
> 
> I believe 4 shades are a safe bet, 3 may be problematic, and 5 may 
be 
> overkill. It is important to note this depends on many variables; 
> among them (1) printer droplet size, (2) printer driver (or RIP) 
> which controls the dither, (3) relationship in color between the 
> paper and the ink, and (5) viewer's visual acuity.
> 
> The modern Epson UC and K3 printer (and the older 1270, 1280 too)
> drivers have a the capacity of very smooth prints, probably because 
> of some proprietary dither algorithms. In comparison, the "Ordered" 
> dither commonly used in QTR produces coarser prints, and therefore 
> require more shades of gray. Try printing black only with QTR and 
> compare with BO using Epson driver and you will see what I mean.
> 
> I am in the process of profiling right now, using the MIS UTFS 
(pure 
> carbon) inks on a 2400 printer, using QTR. I have made custom 
> dilution of the inks to increase the shades from the nominal 4 to 6 
> shades. The papers I am profiling are Hahnemuhle William Turner and 
> German Etching, both fairly warm tone papers. These papers are a 
> wonderful color match to the pure carbon inks, and I must say that 
I 
> see no visual reason to go beyond 3 shades when using 2880 
> dpi, "better" options in QTR. For example at 60% ink limits, I 
start 
> seeing the K (black) dots quite readily at 60% patch, which gets 
> progressively worse at lower patches (brighter). The C (dark gray) 
> dots become visible at the 55% patch. The M (medium gray) dots are 
> virtually invisible even in the 5% patch. So, for this combination 
of 
> printer, paper, ink, QTR at 2880 dpi, 3 shades are essential AND 
> sufficient. My visual acuity (when I take my glasses off) is 
probably 
> the equivalent of a 3X loupe; I focus on a 4x5 camera ground-glass 
> without any aid.
> 
> Another note: If you are using QTR on the original UC (2200, 4000, 
> etc) printers, you will (or at least I do) see dots when printing 
> with "warm" curves, which use just 2 inks (K and LK). But curves 
such 
> as "cool" or "cool-selenium" additonally use LC and LM inks, and 
the 
> dottiness is definitely lower.
> 
> I hope this helps. Best regards and good luck.
> 
> Shilesh
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "dgattarino" 
> <dgattarino@> wrote:
> >
> > Thanks from the few of you who answerd my question.
> > However, none of the replies mentioned the reason for the number 
> they
> > quote as the minimum number black inks for fine art B&W.
> > I made a couple of considerations in the meantime:
> > 1) The gray shades where the print start to look poor ar the 
> lightest.
> > That's where the dots from the print start to become visible.
> > I have never seen such dots in the mid or dark tones
> > 2) From a recent post from Clayton Jones
> > 
> 
(http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/messages/7
> 8918?threaded=1&m=e&var=1&tidx=1)
> > it appears that the gray ink used by far the most is LLK. This 
means
> > that LLK has to cover a larger range of tones by itself, when 
> compared
> > with the other gray inks. Therefore, it might need some "help" 
from
> > another gray shade.
> > 
> > The above considerations would suggest that the minimum number of 
> gray
> > shade for best results is, infact, 4 with a LLLK supplementing 
> Epson's
> > LLK in the highlights.
> > 
> > I would like to know what you think about the above.
> > Thanks. Cheers,
> >    Daniela
> >
>