Digital BW, The Print

Please pardon my ignorance.  What is GCR?

Thanks.

Josh

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "joshhackney" 
<joshhackney@...> wrote:
>
> 
> Please pardon my ignorance.  What is GCR?
> 
> Thanks.
> 
> Josh

Good question.

Grey Component Replacement was for me the use ok K in the grey parts 
of a color image as opposed to Under Color Removal that substracts 
the grey part of the color and replace it by K then just adds what 
can not be replaced by color (in RVB say 124/100/110 -> 24/0/10 + 
grey 100).

But it doesn't seem to be like this for printers and I can't say why.

Olivier

Olivier, nothing personal, but I think something got lost in the translation.  I didn't 
understand a word in your post after "Grey Component Replacement".

Anyone else?

Thank!

Josh

P.S.  Olivier, I do respect you ability to communicate in multiple languages - and at a 
technical level too.  Kudos.  I finally realized why you write RVB - it's not a typo, but 
French - rouge vert bleu!  I'm a little slow, but I eventually catch on.  Thanks anyway.


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Olivier" <odesmais@...> wrote:

>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "joshhackney" 
> <joshhackney@> wrote:
> >
> > 
> > Please pardon my ignorance.  What is GCR?
> > 
> > Thanks.
> > 
> > Josh
> 
> Good question.
> 
> Grey Component Replacement was for me the use ok K in the grey parts 
> of a color image as opposed to Under Color Removal that substracts 
> the grey part of the color and replace it by K then just adds what 
> can not be replaced by color (in RVB say 124/100/110 -> 24/0/10 + 
> grey 100).
> 
> But it doesn't seem to be like this for printers and I can't say why.
> 
> Olivier
>

This is what he tried to explain:
http://en.wikipedia.org/wiki/Grey_component_replacement
I understood, is it because I live on the east side of the atlantic?


Eirik


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "joshhackney" <joshhackney@...> 
wrote:

>
> 
> Olivier, nothing personal, but I think something got lost in the translation.  I didn't 
> understand a word in your post after "Grey Component Replacement".
> 
> Anyone else?
> 
> Thank!
> 
> Josh
> 
> P.S.  Olivier, I do respect you ability to communicate in multiple languages - and at a 
> technical level too.  Kudos.  I finally realized why you write RVB - it's not a typo, but 
> French - rouge vert bleu!  I'm a little slow, but I eventually catch on.  Thanks anyway.
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Olivier" <odesmais@> wrote:
> >
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "joshhackney" 
> > <joshhackney@> wrote:
> > >
> > > 
> > > Please pardon my ignorance.  What is GCR?
> > > 
> > > Thanks.
> > > 
> > > Josh
> > 
> > Good question.
> > 
> > Grey Component Replacement was for me the use ok K in the grey parts 
> > of a color image as opposed to Under Color Removal that substracts 
> > the grey part of the color and replace it by K then just adds what 
> > can not be replaced by color (in RVB say 124/100/110 -> 24/0/10 + 
> > grey 100).
> > 
> > But it doesn't seem to be like this for printers and I can't say why.
> > 
> > Olivier
> >
>

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Eirik Berger" 
<eirik@...> wrote:
>
> This is what he tried to explain:
> http://en.wikipedia.org/wiki/Grey_component_replacement
> I understood, is it because I live on the east side of the atlantic?
> 
> 
> Eirik
> 
Thanks Eirik and sorry for the non-translation. 

Meanwhile, if one has further pratical explanation at the printer 
level, I'd be glad to better understand the process.

Olivier
French

Eirik,

That was perfect.  Thanks for the help.

Didn't mean to take a shot at anyone who speaks english as a second language.  It was my 
frustration at not understanding the technical issue.  My apologies to all - particularly 
Olivier.

Josh   	


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Eirik Berger" <eirik@...> wrote:

>
> This is what he tried to explain:
> http://en.wikipedia.org/wiki/Grey_component_replacement
> I understood, is it because I live on the east side of the atlantic?
> 
> 
> Eirik
> 
>

On 24.3.2006, at 10:54, Olivier wrote:

> Meanwhile, if one has further pratical explanation at the printer
> level, I'd be glad to better understand the process.

The inklimit for inkjet printers is very low - typically 240-280 %.  
It means the printer may drop only such amount of particular inks  
that they sum is not bigger than inklimit. If more, the ink will stay  
on surface of paper, flow, etc.

So it is very important if it will print the 100 % C + 100 % M + 80 %  
Y or 40 % C + 40 % Y + 20 % Y + 60 % K to print the same shadow. In  
first case the amount of ink is 280 %, in second 160 %. In the second  
case you may add 40 % black for deeper shadow. The real world  
printing is not so simple but as an explanation it is enough I hope.

Martin

> The inklimit for inkjet printers is very low - typically 240-280 
%.  
> It means the printer may drop only such amount of particular inks  
> that they sum is not bigger than inklimit. If more, the ink will 
stay  
> on surface of paper, flow, etc.
> 
> So it is very important if it will print the 100 % C + 100 % M + 80 
%  
> Y or 40 % C + 40 % Y + 20 % Y + 60 % K to print the same shadow. 
In  
> first case the amount of ink is 280 %, in second 160 %. In the 
second  
> case you may add 40 % black for deeper shadow. The real world  
> printing is not so simple but as an explanation it is enough I hope.
> 
> Martin
>

Martin, thanks for the info. Could you possibly direct me to a site 
for further knowledge.

Olivier

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Olivier" 
<odesmais@...> wrote:
> 
> Martin, thanks for the info. Could you possibly direct me to a site 
> for further knowledge.
> 
> Olivier
>

I'll see if I can find some links this weekend. I have a few in a 
folder on a machine somewhere....

> >
> 
> I'll see if I can find some links this weekend. I have a few in a 
> folder on a machine somewhere....
>

I know I'm not supposed to just post for it : but thanks for your 
help.

So to add something of general interest, I've just by curiosity 
tested K3 Dmax vs iQuad Piezo :

K3 : 1,73 on EEM vs Piezo at best 1,65 (usually closer to 1,6 to 
prevent blocked shadows with QTR).

Neutrality (though subjective) is far better with K3 (based on only 
using K,LK,LLK) than Piezo neutral warm. I need to mention Piezo K is 
Museum.

I strongly suspect some non-carbon pigments in K3, but WIR reports 
great longevity anyway.

Olivier