QTR-Quadtone RIP

Tyler Boley wrote:

>--- In QuadtoneRIP@yahoogroups.com, Ernst Dinkla <E.Dinkla@c...> wrote:
>...
>  
>
>>I think that using 
>>more heads + less dilutions of black  ink + effective use of droplet 
>>sizes and actually using the mix you get from heads weaving (as intended 
>>in the printer design) will in the end deliver less banding, better 
>>linearisation, more consistency in time. I have written this before in 
>>relation to BO printing and on the K7 threads.
>>    
>>
>
>Are you speaking of using different density K inks in parallel rather than partitioned series, 
>or some combination of the two?
>We discussed this once before, I thought the BO users could benefit from a the more 
>complex dither that would result. I never got the chance to test it. Life is getting too short 
>for all this testing.
>Actually, can you assign two inks to the same part of the scale in QTR?
>  
>

I've used a quad setup on the 9000 that had the Eboni black + the middle 
grey ink in the Mm channels and was linearised like that and in the Cc 
channels, the darkest grey + lightest grey ink in Mm and linearised like 
that again. Some partitioning was laid on top of that, (the highlights 
were done by the lightest range only, mixing of the two ranges was of 
course mainly in the mid ranges, 2% of the darkest grey went up with the 
black) trying to get as close to native linearisation and an overall 
linearisation etc added afterwards. Wasatch SoftRip. That's a simple 
example of what I propose. BTW, Paul Roark's PS curves and ink mixes 
must have had a similar structure.
The crudest example is having 4 black inks in a C86 for BO, that will 
give you a nozzle quantity that comes near 360 if I recall it correctly.
On a K7 printer and with QTR you could make one K4 range and a K3 ink 
range, linearise them and mix them with the slider. The 5 partitioning 
points of the two ranges are all overlapped, and you get weaving of two 
heads on any spot. Depending on the droplet sizes available (resolution) 
and the partitioning the droplet size transfer points could overlap as 
well. If you use the normal K7 inks then you would expect more visible 
dots in the highlights but I think it will not be much more visible. You 
will loose the possibility to mix toner in but that's not available in 
the K7 set anyway. No need to change inks. Ink distribution may benefit 
from the original CMYK weaving positions though, for example the K3 in 
the CcY lines the K4 in the KkMm lines. In a way these overlapping quads 
resemble the B&W films with two or more emulsion layers.

I have no idea how the K7 inks are distributed on the ink positions, if 
they use the two main lines as sketched above and given that the overlap 
in the partitions is already relatively wider as one head only covers 
about 14% of the total range, the result may be close to having two 
ranges next to one another. The ink distribution something like K7-K, 
K6-C, K5-k, K4-c, K3-M, K2-Y, K1-m. If that's happening already then I 
shouldn't worry about the K7 concept.

No,  I don't think you can assign two inks to the same part in QTR, I 
have asked that once and got an answer by Carl or Daniel but couldn't 
figure it out or my question wasn't understood. I think it would be good 
if QTR allowed the use of multiple heads for the same task.

Ernst