Digital BW, The Print

At 04:58 +0000 25.10.2003, Clayton Jones wrote:
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>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
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