QTR-Quadtone RIP

I think I understand what I'm seeing here. It reminds one that using 
more dilutions of black will give one diminishing returns. But, we as a 
group are all about getting the very best we can out of our printing.

This begs the question: How many is too many? People I trust tell me 
that there's a clearly visible advantage in going from four inks to six. 
Is there a visible advantage in going from six inks to seven? eight? twelve?
--
Bruce Watson


Roy Harrington wrote:

> Here's a couple of examples of what partitioning looks like for 2, 4,
> and 7 grays.
> They are crude text graphs but show that at all times there are 2 or 3
> inks being used.
> Down the page are the K percents,  across is amount of each ink used.
>
> A quad system:
>
>    0   0%  |
>    5   2%  | Y
>   10   4%  |  Y
>   15   6%  |    Y
>   20   8%  |     Y
>   25  10%  |       Y
>   30  12%  |        Y
>   35  14%  |          Y
>   40  16%  |            Y
>   45  18%  |              Y
>   50  20%  |                 Y
>   55  22%  |                   Y
>   60  24%  |                      Y
>   65  25%  |                         Y
>   70  27%  |                             Y
>   75  29%  |M                               Y
>   80  31%  |M                                   Y
>   85  33%  | M                                     Y
>   90  35%  | M                                       Y
>   95  37%  |   M                                      Y
> 100  39%  |    M                                     Y
> 105  41%  |      M                                   Y
> 110  43%  |         M                                Y
> 115  45%  |           M                             Y
> 120  47%  |               M                       Y
> 125  49%  |                    M               Y
> 130  51%  |                           M  Y
> 135  53%  |                      Y             M
> 140  55%  |C               Y                        M
> 145  57%  | C            Y                           M
> 150  59%  |  C         Y                               M
> 155  61%  |   C      Y                                  M
> 160  63%  |   C    Y                                     M
> 165  65%  |     CY                                         M
> 170  67%  |   Y  C                                          M
> 175  69%  |Y       C                                         M
> 180  71%  |           C                                   M
> 185  73%  |              C                            M
> 190  75%  |                  C                     M
> 195  76%  |                   C                   M
> 200  78%  |                       C           M
> 205  80%  |                        M         C
> 210  82%  |                   M                   C
> 215  84%  | K          M                                C
> 220  86%  |   K    M                                      C
> 225  88%  |    KM                                          C
> 230  90%  |  M   K                                           C
> 235  92%  |            K                                C
> 240  94%  |                  K                    C
> 245  96%  |                            K C
> 250  98%  |        C                                                K
> 255 100%  |   C                                                        
>           K
>
>
> Finally the K7 system:
>
>    0   0%  |
>    5   2%  |              Y
>   10   4%  |m                            Y
>   15   6%  | m                                        Y
>   20   8%  |      m                                       Y
>   25  10%  |             m                                Y
>   30  12%  |                      m                   Y
>   35  14%  |                                 m Y
>   40  16%  |                         Y                     m
>   45  18%  |  M               Y                                    m
>   50  20%  |      M     Y                                              m
>   55  22%  |      Y    M                                                
>   m
>   60  24%  | Y              M                                           
>    m
>   65  25%  |                        M                                m
>   70  27%  |                                  M             m
>   75  29%  |                                      m     M
>   80  31%  |c                           m                         M
>   85  33%  |  c                    m                                 M
>   90  35%  |     c             m                                       M
>   95  37%  |       c      m                                             
> M
> 100  39%  |         cm                                                 
>    M
> 105  41%  |      m     c                                               
>     M
> 110  43%  | m              c                                           
>       M
> 115  45%  |                    c                                       
>   M
> 120  47%  |                          c                              M
> 125  49%  |                               c                   M
> 130  51%  |                                     c       M
> 135  53%  |                                       M    c
> 140  55%  |                                M                  c
> 145  57%  | C                       M                               c
> 150  59%  |    C               M                                     c
> 155  61%  |       C        M                                           c
> 160  63%  |          CM                                                
>   c
> 165  65%  |     M        C                                             
>     c
> 170  67%  |                    C                                       
>    c
> 175  69%  |                              C                     c
> 180  71%  |                                        C c
> 185  73%  |                                 c                C
> 190  75%  |k                     c                                     C
> 195  76%  |    k           c                                           
>   C
> 200  78%  |         kc                                                 
>     C
> 205  80%  |  c            k                                            
>       C
> 210  82%  |                          k                             C
> 215  84%  |                                      k     C
> 220  86%  |                               C                   k
> 225  88%  | K                C                                         
>     k
> 230  90%  |    K       C                                               
>       k
> 235  92%  |       CK                                                   
>         k
> 240  94%  | C          K                                               
>           k
> 245  96%  |                      K                                     
> k
> 250  98%  |                                          kK
> 255 100%  |       k                                                    
>                                    K
>
> Roy
>
> -
> Roy Harrington
> roy@...
> Black & White Photo Gallery
> http://www.harrington.com
>