QTR-Quadtone RIP

I’m not sure about other printers but I use the front feed option on the Epson 3800. The pizza wheels do not engage in this mode. I print a lot of negatives for salted paper which has a very dense negative. This had always given me problems before I started using the front feeder.

Alan

> On Jan 28, 2015, at 2:19 PM, sanking@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> It may well be that that dither pattern is more the source of roughness than the dots themselves.  If all the inks are in identical curves, each channel may be using the same dither pattern, accentuating whatever pattern is there.  
> 
> 
> This seems to run counter to the earlier observation that more dark inks firing at the same time turns the ordered pattern into a random one that is seen are rougher.  Some empirical experimentation may be needed to see which way this cuts and at what levels.  
> 
> Interesting speculation that the use of identical curves may accentuate the dither pattern. That is definitely worth testing. In my previous digital negative profiles with Epson K3 inks I set ink levels so that UV blocking of the only useful inks (PK, Y and LK) matched. This of course produced different curves.
> 
> The major problem area for me in making digital negatives with inkjet printers is not smoothness, but in how fast and hard the inks dry, especially in using the small printers that use the pricked wheel to guide the media. If the inks does not dry fast enough the wheels will prick the ink and cause what is known as pizza wheel marks. If it does not dry hard the negative can be damaged. 
> 
> I have yet to find a way an easy way to make a perfect digital negative, so any and all suggestions of a theoretical nature that can be empirically tested are much appreciated.
> 
> Sandy
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>