Sm102 image controller tuning.

[Cal]

Hi, we are doing some colour profiling between pre press and press currently, and I would like to know how to alter the overall solid density of the black on the Heidelberg image controller. I'm not talking about reference values. When matching proofs to press images, all colours definitely look visually too strong. ( SOLID areas). The black being slightly stronger again. Since changing inks recently, it appears that the ink we are currently using is quite a significant amount stronger.. So before colour profiling is carried out by our pre press, shouldnt we be making sure that the solid densities look visually similar first? Thanks for any help.

 

[Diagramamen]

I think your new paint supplier might be able to answer that question.
Nobody better than the manufacturer of a product to clarify the doubts concerning.
He is the most interested that you succeed because this guarantees new orders of the product.
This rule fits logically when it is a suitable supplier and that dominates the characteristics of the product.

 

[asem alsafady]

Dear cal,
You have to make a new color set, either with a printed sheet (good densities) that has a control strip from actual job, or printed samples that have good densities.
Or you can edit the LAB values for the new OK colors, and save them.

 

[Cal]

Asem,

Thanks alot for the reply, and quickly answering my question.

Should the new colour set be created while printing colour profiling plates using coated stock and uncoated to achieve a visually similar solid density first. And once created and using this colour set it shouldn't need to be altered theoretically using the same brand ink, I imagine?.

Obviously new blankets, resetting of any rollers and using a a stock like alpine white or similar to start with.

Is there anything else to check or something I should be ensuring happens before running a set of Linear plates from our pre-press on the last four colour printing units on the speedmaster 102. Any tips would be most appreciated.

The printed result from the colour profiling run is then scanned and will now be able to tell you your dot gain correct? what sort of amounts are suitable? Minimal? I'm sorry pre press understanding of things and what they do in there are unfortunately pretty limited. So bare with me while trying to learn and understand the aspects involved for setting up and maintaining the best possible colour management system.

I mostly always see red numbers on the DG80 percentage column on all units which is an indicator that it's excessive I'm sure..
Do we try to achieve minimal dot gain on the image controller display in the 80% screen areas first, or is some dot gain required which is what enables the pre press department to alter the dot to ensure a neutral 3 colour grey aswell as a very similar image colour match from proof to paper.

 

[Cal]

Should we be profiling the machine on the colour inkking units before and after the perfector or is after the perfector alone still fine. Once we're happy with the solid colour areas and images are just about matched, is that all that is required as I'm not sure of the best method for the entire process.

 

[asem alsafady]

Dear Cal,
I guess you are using Image Control 1.
The first step, you have to know the optimum densities for your CMYK inks from your ink supplier.
Now you can make new color set.
- Create a job at the prepress that contains high image area for all your process colors and for sure with a color bar, then follow the required densities using your manual densitometer, then you have to measure this sheet at your Image Control, from Service choose color from sample, new color set, point at the better area which best match your required density (be careful here and point at the middle exactly), choose the color from the table, color from color bar, confirm.
You have to repeat this process using uncoated paper.
You don't have to change your color set if you are using the same inks.
Now your Image Control is ready to follow the new densities.
Finally, are you asking about making a process calibration, if yes send me at:
asemalsafady@yahoo.com.
Regards from hot Jordan.