Digital BW, The Print

Paul Roark wrote:
> With the 220, QTR, Eboni, and Premier Art Matte BW I hit 1.7 with both 1440
> and 2880.  The 1440 has lines in it and takes 100% load.  The 2880 is smooth
> and hits the dmax before the 100% load.  If you're using 1440, try 2880 and
> print a ramp to see where your dmax is.
> 
>  
> 
> My experience with modern printers is that under-printing only increases
> dmax where the  matte black ink is not covering properly.  If the MK is
> being properly applied, under-printing always decreases dmax.  QTR (actually
> Gimp print, I assume) at 1440 may be one of those situations where the ink
> is simply not being properly applied in many if not most situations.  My
> solution is to avoid 1440 with QTR (or other Gimp print driver) and avoid
> under-printing.

I think it is always a compromise with the two highest 
resolutions. The same droplet size will be used and the 
highest resolution will have slightly too much ink and the one 
below it just not enough. Placing of the dots can't compensate 
that enough. I see it on the 9000's with their one droplet 
size and I see it on the 10000 with more droplet sizes. On 
lower resolutions the other droplet sizes may take over but I 
guess it will be in pairs of two resolutions as well. Roy must 
have some understanding of what is selected in droplet size 
over the range of resolutions.

If bidirectional works well on a printer one could try that 
instead of unidirectional, the slightly higher bleeding then 
may suppress the white lines (too little overlap) but at the 
same time a bit less ink is used as in the highest resolution. 
Of course for that you have to select the second highest 
resolution. Most of the time the bidirectional settings is 
less well aligned and the inks are laid down in reversed order 
on the back stroke. The last is probably not a problem with 
quad inks. In color printing it influences the color mix.


Met vriendelijke groeten,Ernst


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