QTR-Quadtone RIP

Roy, you wrote:

>
>But it's interesting that with the K7 inks its noticibly (but not much) better to use
>2880dpi with only one dropsize rather than 1440dpi which is using two sizes.
>I think its because the 2X difference in drop size is as big as the difference
>between ink densities.
>
>  
>
Which to me means that the K7 inkset is already stretching the ink 
partitioning too far.  Better linearisation of the droplet transfer 
points should deliver equal quality with less ink dilutions. There's 
also no advantage in consistency by having one droplet size over the 
entire range. In practice this means the smallest droplet and that one 
is more prone to visible dotgain when humidity, coating qualities etc 
vary. John Dean described what was used for duotone offset printing and 
that had much to do with dotgain increase of small dots at 30% and up so 
a coarser dot formation is used there to diminish the area/circumference 
ratio and by that dotgain/bleeding. Resolution suffers then but it would 
be hit by bleeding as well and at least  the density can now be 
controlled. Solving the dotgain issues of stochastic printing in offset 
wasn't possible without strict control of all the variables and in 
practice hybrids of halftone and stochastic printing were introduced to 
make the process more stable. In the shadows the dotgain isn't reduced 
by diluted inks either, the effect is as it is with  BO printing at that 
point.

Ernst