Creating calibration curves and Ink

[maac]

I would like to talk with a member who has the Heidelberg SM-52 Anicolor press in the shop. And understands the ink unit technology zooneless inking (hot/cold). The yellow, Magenta,Cyan,and Black they are linearized 50% is 50% 10% 10% and 90% is 90% and so on. With the press curves applied after to the plates from the sheet off the press. After this step as you know you still need to cut the calibration back (-12% on the yellow and -7% on the Mag,Cyan,Black. So if the 50% dot reads 51.25% I still cut the dot back to 39.25% What I need input on is the Ink from one ink supplier to another.

thanks

 

[gordo]

I would like to talk with a member who has the Heidelberg SM-52 Anicolor press in the shop. And understands the ink unit technology zooneless inking (hot/cold). The yellow, Magenta,Cyan,and Black they are linearized 50% is 50% 10% 10% and 90% is 90% and so on. With the press curves applied after to the plates from the sheet off the press. After this step as you know you still need to cut the calibration back (-12% on the yellow and -7% on the Mag,Cyan,Black. So if the 50% dot reads 51.25% I still cut the dot back to 39.25% What I need input on is the Ink from one ink supplier to another.

thanks

For clarification...
1 - Your desire is that a 50% request in the native file will end up as 50% on the press sheet? i.e. you want to print linear?
2 - You linearize your plates with a plate curve so that 50% in the native file will end up as 50% on the plate?
3 - You apply a press curve on top of your plate curve so that 50% in the native file will end up as 39.25% on the plate so that 50% in the native file will end up as 50% on the press?
4 - Could you explain what you mean by: "What I need input on is the Ink from one ink supplier to another." Are you switching to a new ink supplier?

 

[maac]

Thanks for getting back with me but I need to know do you run the Heidelberg SM-52 Anicolor press or do you have the press in the shop and you setup the calibration for that press ?. And understands the ink unit technology zooneless inking.

To answer your questions.
1- no we do not want to print linear.
2- yes we linearize the plates first so the 50% is 50% on the plate.
3- yes we apply a press curve on top of the plate curve.
4- yes we did. one ink supplier to another. when the press was first installed we had the ink from the manufacturer. then they made a change and now they change the ink again. and we do re-calibrate each time.

 

[maac]

If this help to understand what we have on the cut back and it all works great on the press the color is great.

 

[kansasquaker]

Maac-

It sounds to me like the manufacturer gave you a down and dirty color profile. If you're ok with how it looks on press, then great. If you're trying to match a known specification, then that probably isn't so great. Both of those statements are true regardless of what ink you use.

If you switch inks the color will also shift. If you redo this profiling procedure with the new ink, your color may not (probably won't) match what you previously printed. That's because you're profiling for absolute TVI and not the color of the print. The degree of mismatch in color will be correlated to the degree of mismatch between the two ink sets. For example, if you switch to an inkset with a stronger magenta but keep the desired output of magenta at 43, your midtones will be more pink than they were before.

The alternative approach would be to put linear plates on your press, measure the output and create curves to match Gracol or SWOP etc.

 

[gordo]

If this help to understand what we have on the cut back and it all works great on the press the color is great.

Personally I think your linearizing plate curve is redundant.

That being said, is this correct?

2014-0922-Linear Plate.cal = Plate Curve to linearize plate.

SM52_ink_cutback.cal = Press Curve to apply after applying linearizing curve to deliver desired dot gain on press.

So what is:

“S52-COATED-2014-0710_b”

 

[maac]

gordo: thanks for your help I have read most of your notes on color calibration and the best way to apply the curve to the press. We have 2 Heidelberg 74s and 1 Komori-28 and 1 Ryobi. But what I need the help on is the (Heidelberg SM-52 Anicolor press) do you know a member who runs that press. I could sure used your help on that.

Michael

 

[Johu]

There certainly must be members with that press. But looking at the image you posted (work.pdf) what struck odd to me was the notion that "density will change with the speed of the press". How do you maintain a constant quality if you need to change the speed of the press for whatever reason? Is this normal for anicolor presses?

 

[maac]

thanks on all other types of presses you can just cut back the ink. The Anicolor works off of a chiller and when the ink is chilled it is thick so less ink will run on the sheet. And when the ink is warmed up more ink will run onto the sheet I think.