Dot Gain and Curves, OH MY!

[pacart]

I need help!!

I am a newbie at this we are trying to get the press dialed in so here is the info.

Densities that the pressman run:

C=135
M=145
Y=100
K=170

The press is a 2 color Ryobi HXX 520. We run yellow and cyan on one unit and magenta and black on the other unit usually. The tests were run with new blankets and packing.

I have created a curve from a run we did with no calibration - this is applied as a compensation curve.

And we also have a curve that is a kodak_2005_swop curve that we are applying as a direct curve.

The paper is a glossy 100# book

The results:

C M Y K
100 100 101 100 100
95 97 100 98 100
90 96 99 96 99
85 94 97 93 97
80 92 94 87 95
75 89 92 84 92
70 86 89 80 90
65 84 87 76 87
60 78 85 72 85
55 73 81 68 81
50 66 77 62 77
45 63 72 57 74
40 57 67 52 69
35 51 61 47 63
30 46 55 42 56
25 40 48 37 49
20 34 39 32 39
15 27 32 25 30
10 20 22 19 21
5 11 12 11 11
0 0 0 0 0

Below are the curves from the uncalibrated run:

As you can see the Black and Magenta curves are pretty flat, not sure if that is ok.

So i don't know where to go from here, not sure if the numbers i am showing are doable, If someone could help me out with a bit of advise written for a 3 year old, that would be helpful. thanks.

 

[mac310]

At the begening the problem is in not standard dot gain but quite big differences betwean separations.
If you print Y & C on one unit and M & K on second one it is visible on your results. In that case you have the dot gain difference betwean printing units. You shoud review press condition and fix problems before you start correction curves. When the problem is stable you can compensate that differences by calibration curves but keep in mind that you will have to use always the same sequence as used during calibration (not to mix colors/units).

 

[VladCanada]

+100 points from mine to mac310's opinion.
pacart compares two presses with two different conditions...