QTR-Quadtone RIP

A friend showed me a profile for a particular printer which uses 7 inks. Here's part of it:

LIMIT_K=14
LIMIT_C=14
LIMIT_M=25
LIMIT_Y=18
LIMIT_LC=40
LIMIT_LM=25
LIMIT_LK=40

The "LIMIT" numbers express the relative ratio of inks (correct me if I'm wrong), but added together they exceed 100%: the sum is actually 176.  

I presume those numbers come from an examination of the patches on the QTR "Ink Pattern Page". 

Does the QTR engine reduce these to relative percentages ? 

K  = 8%
C  = 8%
M = 14%
Y =  10%
LC = 23%
LM = 14%
LK = 23%
------------------ 
Total:  100%

If so, would the following work just the same ?

LIMIT_K=8
LIMIT_C=8
LIMIT_M=14
LIMIT_Y=10
LIMIT_LC=23
LIMIT_LM=14
LIMIT_LK=23

No because the theoretical limit for each ink is 100, and you can put more than 100% total down if you want, as in your friends profile, if all inks were applied at the same time at their limits which is probably not the case..

David



________________________________

 From: kenleegallery <kenlee333@...>
To: QuadtoneRIP@yahoogroups.com 
Sent: Monday, 23 January 2012 11:50 AM
Subject: [QuadtoneRIP] QTR "LIMIT_" parameters: relative or absolute ?
 

  
A friend showed me a profile for a particular printer which uses 7 inks. Here's part of it:

LIMIT_K=14
LIMIT_C=14
LIMIT_M=25
LIMIT_Y=18
LIMIT_LC=40
LIMIT_LM=25
LIMIT_LK=40

The "LIMIT" numbers express the relative ratio of inks (correct me if I'm wrong), but added together they exceed 100%: the sum is actually 176. 

I presume those numbers come from an examination of the patches on the QTR "Ink Pattern Page". 

Does the QTR engine reduce these to relative percentages ? 

K  = 8%
C  = 8%
M = 14%
Y =  10%
LC = 23%
LM = 14%
LK = 23%
------------------ 
Total:  100%

If so, would the following work just the same ?

LIMIT_K=8
LIMIT_C=8
LIMIT_M=14
LIMIT_Y=10
LIMIT_LC=23
LIMIT_LM=14
LIMIT_LK=23


 

[Non-text portions of this message have been removed]

no, they aren't reduced to add to 100%.

maximum black doesn't have all inks at the limit, but probably only the 
darkest. You can examine the curves used (somewhere in qtrgui on the PC, 
not sure about the Mac) and you'll see that there is a very limited 
crossover between inks where more than one ink is used to generate the 
shades of grey. (ignoring toners that tune the colour rather than density).

(i've been toying with the idea of trying to create curves with a 
greater overlap to see if the results are smoother. The published curves 
for the piezography inks show a wider overlap.)

On 22/01/2012 22:50, kenleegallery wrote:
>
> A friend showed me a profile for a particular printer which uses 7 
> inks. Here's part of it:
>
> LIMIT_K=14
> LIMIT_C=14
> LIMIT_M=25
> LIMIT_Y=18
> LIMIT_LC=40
> LIMIT_LM=25
> LIMIT_LK=40
>
> The "LIMIT" numbers express the relative ratio of inks (correct me if 
> I'm wrong), but added together they exceed 100%: the sum is actually 176.
>
> I presume those numbers come from an examination of the patches on the 
> QTR "Ink Pattern Page".
>
> Does the QTR engine reduce these to relative percentages ?
>

-- 
mike finley photography
http://www.mikefinley.co.uk
http://words.mikefinley.co.uk



[Non-text portions of this message have been removed]

Thanks for explaining that. 

Does DEFAULT_INK_LIMIT limit the *total* amount of ink laid down - or does it specify a limit that no single ink can exceed?

If we specify the amount of each ink, then why bother with a default number? If we specify a limit for every ink, is the default limit ignored or irrelevant ?   

--- In QuadtoneRIP@yahoogroups.com, 228044881 228044881 <cheesecraft@...> wrote:

>
> No because the theoretical limit for each ink is 100, and you can put more than 100% total down if you want, as in your friends profile, if all inks were applied at the same time at their limits which is probably not the case..
> 
> David
> 
> 
> 
> ________________________________
>  From: kenleegallery <kenlee333@...>
> To: QuadtoneRIP@yahoogroups.com 
> Sent: Monday, 23 January 2012 11:50 AM
> Subject: [QuadtoneRIP] QTR "LIMIT_" parameters: relative or absolute ?
>  
> 
> Â  
> A friend showed me a profile for a particular printer which uses 7 inks. Here's part of it:
> 
> LIMIT_K=14
> LIMIT_C=14
> LIMIT_M=25
> LIMIT_Y=18
> LIMIT_LC=40
> LIMIT_LM=25
> LIMIT_LK=40
> 
> The "LIMIT" numbers express the relative ratio of inks (correct me if I'm wrong), but added together they exceed 100%: the sum is actually 176. 
> 
> I presume those numbers come from an examination of the patches on the QTR "Ink Pattern Page". 
> 
> Does the QTR engine reduce these to relative percentages ? 
> 
> K  = 8%
> C  = 8%
> M = 14%
> Y =  10%
> LC = 23%
> LM = 14%
> LK = 23%
> ------------------ 
> Total:  100%
> 
> If so, would the following work just the same ?
> 
> LIMIT_K=8
> LIMIT_C=8
> LIMIT_M=14
> LIMIT_Y=10
> LIMIT_LC=23
> LIMIT_LM=14
> LIMIT_LK=23
> 
> 
>  
> 
> [Non-text portions of this message have been removed]
>