QTR-Quadtone RIP

>
> I have an off-beat request: I'm trying to create, on transparency film, an image made up of dots, where the darker tones have the dots spaced closer together and the lighter tones have the dots spaced farther apart. 
> 
> I'm using this to create a photopolymer etching plate; for those unfamiliar with this, its probably most similar to screen printing, 
> 
> Using QTR, I'd be printing these at 720 or 1440 ppi. 
> 
> Here's the kicker: I'd like EACH DOT to be the same color, using about 94% magenta and 75% yellow ink. (The range of tones in my image file range from about 80% to white, so there is no pure black and no place in the image where the dots would totally fill up the space.)  
> 
> Could someone tell me what density and ink limit settings I'd need for both the magenta and yellow inks. 
> 
> I'm a novice to QTR. I asked this question a few years ago, but I'm not getting the results I need based on past advice. 
> 
> kind regards, david 
> 
> Best, David.
>

>
> Hi david,
> 
> I've made digital positives for photopolymer intaglio prints with QTR with good success.
> 
> I'm not sure if you count on QTR to create the aquatint dithering. Anyhow, at least given your requirements, it will not. You will have to create the dithering pattern in eg photoshop. I use andromeda screen filter for this. The result should be a black and white image (no gray tones). The dots are formed in Photoshop, not QTR. Any consideration with respect to percentage coverage of the dithering pattern is to be handled in photoshop, again not in QTR.
> 
> Next you'll have to create a QTR curve. I suggest you read Tom More's manual. In your case, it's actually much simpler than a normal curve as you should only be concerned by the blacks, as the image does not contain any gray levels. Apperently, you already know you need magenta and yellow in a certain ratio. But be carefull not to overload, I would be concerned that a curve with 94% of the maximumlevel of one ink + 75% of the other would be way more then the medium can absorp. 
> 
> What are you printing on? I have printed on Agfa Copyjet. After some experiments it turned out that in my case just matte black gave the highest density. Any experiments with photoblack and magenta gave much less density. But I guess that's very dependent on the situation.
> 
> Joost
>  
> 
> 
>  
> 
> --- In QuadtoneRIP@...m, "David" <dkfreed@> wrote:
> >
> > I have an off-beat request: I'm trying to create, on transparency film, an image made up of dots, where the darker tones have the dots spaced closer together and the lighter tones have the dots spaced farther apart. 
> > 
> > I'm using this to create a photopolymer etching plate; for those unfamiliar with this, its probably most similar to screen printing, 
> > 
> > Using QTR, I'd be printing these at 720 or 1440 ppi. 
> > 
> > Here's the kicker: I'd like EACH DOT to be the same color, using about 94% magenta and 75% yellow ink. (The range of tones in my image file range from about 80% to white, so there is no pure black and no place in the image where the dots would totally fill up the space.)  
> > 
> > Could someone tell me what density and ink limit settings I'd need for both the magenta and yellow inks. 
> > 
> > I'm a novice to QTR. I asked this question a few years ago, but I'm not getting the results I need based on past advice. 
> > 
> > kind regards, david 
> > 
> > Best, David.
> >
>

> 
> --- In QuadtoneRIP@yahoogroups.com, "horstenj" <j.h.j.h@> wrote:
> >
> > Hi david,
> > 
> > I've made digital positives for photopolymer intaglio prints with QTR with good success.
> > 
> >I use andromeda screen filter for this. The result should be a black and white image (no gray tones). The dots are formed in Photoshop, not QTR. Any consideration with respect to percentage coverage of the dithering pattern is to be handled in photoshop, again not in QTR.

>
> Joost, which Andromeda filter did you use? Is it the mezzotint? I asked them about this, and they said a filter to do what I want is soon to be released, but not available right now. Maybe they don't understand what I want. 
> 
> Best, David. 
> 
> > 
> > --- In QuadtoneRIP@yahoogroups.com, "horstenj" <j.h.j.h@> wrote:
> > >
> > > Hi david,
> > > 
> > > I've made digital positives for photopolymer intaglio prints with QTR with good success.
> > > 
> > >I use andromeda screen filter for this. The result should be a black and white image (no gray tones). The dots are formed in Photoshop, not QTR. Any consideration with respect to percentage coverage of the dithering pattern is to be handled in photoshop, again not in QTR.
>

>
> David,
> 
> I use the Andromeda "screens" filter. I notice they changed their website at the expense of a decent explanation. This link:
> 
> http://www.andromeda.com/main/screengall_screens.php
> 
> gives some idea. I guess it's the same filter as your call "mezzotint". I use it to create an aquatint-like dithering, which is noticably different than a stochastic dithering. Given the same resolution the aquatint has a coarser, but more natural/artistic feel then a stochastic dithering.
> 
> If you want stochastic dithering indeed, there are several (free) photoshop plugins that do that.
> 
> Joost
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "David" <dkfreed@> wrote:
> >
> > Joost, which Andromeda filter did you use? Is it the mezzotint? I asked them about this, and they said a filter to do what I want is soon to be released, but not available right now. Maybe they don't understand what I want. 
> > 
> > Best, David. 
> > 
> > > 
> > > --- In QuadtoneRIP@yahoogroups.com, "horstenj" <j.h.j.h@> wrote:
> > > >
> > > > Hi david,
> > > > 
> > > > I've made digital positives for photopolymer intaglio prints with QTR with good success.
> > > > 
> > > >I use andromeda screen filter for this. The result should be a black and white image (no gray tones). The dots are formed in Photoshop, not QTR. Any consideration with respect to percentage coverage of the dithering pattern is to be handled in photoshop, again not in QTR.
> >
>

On Wed, Nov 25, 2009 at 10:00 AM, David <dkfreed@...> wrote:
> Thanks again Joost.
>
> I have already tried the rastus plugin, but didn't get the results I needed. There is another program called Icefields, but it is only for Mac. I'm looking into whether I can run it on my PC using Mac emulator software.
>
> Getting back to my original question, I'd still like to know the settings/curves in QTR, so that each dot of ink laid down is a certain mix of two color inks, say magenta and yellow, or cyan and magenta; so if I printed a bit mapped image the dots of ink would be this color combination, bit the spaces in between would be blank.
>
> Best, David.
>
>
> --- In QuadtoneRIP@yahoogroups.com, "horstenj" <j.h.j.h@...> wrote:
>>
>> David,
>>
>> I use the Andromeda "screens" filter. I notice they changed their website at the expense of a decent explanation. This link:
>>
>> http://www.andromeda.com/main/screengall_screens.php
>>
>> gives some idea. I guess it's the same filter as your call "mezzotint". I use it to create an aquatint-like dithering, which is noticably different than a stochastic dithering. Given the same resolution the aquatint has a coarser, but more natural/artistic feel then a stochastic dithering.
>>
>> If you want stochastic dithering indeed, there are several (free) photoshop plugins that do that.
>>
>> Joost
>>
>>
>> --- In QuadtoneRIP@yahoogroups.com, "David" <dkfreed@> wrote:
>> >
>> > Joost, which Andromeda filter did you use? Is it the mezzotint? I asked them about this, and they said a filter to do what I want is soon to be released, but not available right now. Maybe they don't understand what I want.
>> >
>> > Best, David.
>> >
>> > >
>> > > --- In QuadtoneRIP@yahoogroups.com, "horstenj" <j.h.j.h@> wrote:
>> > > >
>> > > > Hi david,
>> > > >
>> > > > I've made digital positives for photopolymer intaglio prints with QTR with good success.
>> > > >
>> > > >I use andromeda screen filter for this. The result should be a black and white image (no gray tones). The dots are formed in Photoshop, not QTR. Any consideration with respect to percentage coverage of the dithering pattern is to be handled in photoshop, again not in QTR.
>> >
>>
>
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>
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>

>
> Hi David,
> 
> The only way to get specific ratios of two inks is to mix the inks by hand and load the
> mixture into one of the ink carts.  The printers only output up to 3 different ink drop sizes so the printer itself can't do what you are asking for.  Inkjet printers in general use dithering to get multiple levels -- your eye does the averaging of a larger area
> than one ink drop.
> 
> QTR doesn't have a way to correlate positioning of different inks.  In
> fact the idea is just the opposite -- eliminate dot patterns by more randomness of dot placement.
> 
> Roy
> 
> 
> On Wed, Nov 25, 2009 at 10:00 AM, David <dkfreed@...> wrote:
> > Thanks again Joost.
> >
> >
> > Getting back to my original question, I'd still like to know the settings/curves in QTR, so that each dot of ink laid down is a certain mix of two color inks, say magenta and yellow, or cyan and magenta; so if I printed a bit mapped image the dots of ink would be this color combination, bit the spaces in between would be blank.
> >
> > Best, David.

On Wed, Nov 25, 2009 at 2:21 PM, David <dkfreed@whidbey.com> wrote:
> Thanks Roy -- finally, the answer! Its just a guess on my part, but I'm wondering if the random dot placement of inkjet printers is why they don't print bit-map images all that well, and often print them very dark? (And why I'm having so much trouble getting the results I want)
>
> best, david
>
>
> --- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@...> wrote:
>>
>> Hi David,
>>
>> The only way to get specific ratios of two inks is to mix the inks by hand and load the
>> mixture into one of the ink carts.  The printers only output up to 3 different ink drop sizes so the printer itself can't do what you are asking for.  Inkjet printers in general use dithering to get multiple levels -- your eye does the averaging of a larger area
>> than one ink drop.
>>
>> QTR doesn't have a way to correlate positioning of different inks.  In
>> fact the idea is just the opposite -- eliminate dot patterns by more randomness of dot placement.
>>
>> Roy
>>
>>
>> On Wed, Nov 25, 2009 at 10:00 AM, David <dkfreed@...> wrote:
>> > Thanks again Joost.
>> >
>> >
>> > Getting back to my original question, I'd still like to know the settings/curves in QTR, so that each dot of ink laid down is a certain mix of two color inks, say magenta and yellow, or cyan and magenta; so if I printed a bit mapped image the dots of ink would be this color combination, bit the spaces in between would be blank.
>> >
>> > Best, David.
>
>
>
>
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