Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Martin Sluka 
<martinsluka@m...> wrote:
> At 04:58 +0000 25.10.2003, Clayton Jones wrote:
> *******************************************
> 
> >But don't use that as an excuse to dump on
> >the BO technique.  It's blacks are surpassed by none.  You can't get
> >any blacker than 100% coverage with 100% black ink.
> >
> >Regards,
> >Clayton
> 
> I apologize, but I don't ahree with you. Not by my personal 
> experience but because of simple mathematics:
> 
> The best inkjet for giclee - IRIS and its clones - produces as large 
> as 96 pl dots (firing all 36 possible 3 pl drops in one place). 
> 2200/2100 has largest drop only 22 pl - about 4,5 times less. Simple 
> if you use only BO 100 % black ink only and if you use 100 of all 
> black inks of quadtone system you should receive black with higher 
> density in second case. Any black pigment one may use is not 100 % 
> black (only black hole does it) --> more black pigment = more black.
> 
> Amount of ink from OB drop: 22 pl
> amount of ink of 75 % black ink: 22*0.75 = black as 16,5 pl of 100 % black ink
> amount of ink of 50 % black ink: 22*0.50 = black as 11 pl of 100 % black ink
> amount of ink of 75 % black ink: 22*0.25 = black as 5,5 pl of 100 % black ink
> 
> 22+16,5+11+5,5 = 55 pl of black as 100 % black ink >>> 22 pl
> 
> There are physical reasons (capacity of coating) you may not achieve 
> the 400 % of inks usually.
> 
> Martin Sluka
> --

The Epson printers are capable of printing the maximum volume of ink
that paper can handle using just one ink.  So like Clayton said the best
dMax is achieved using just the black ink -- otherwise you'd have to
reduce the black ink in order to add any of the others.

From personal experience, the Epson driver achieves the darkest dMax
when used in the black-only mode.  With other drivers/RIPs its may be
possible to achieve this in other modes.

Roy