How do I "fix" maximum ink density

[1106design]

I'm working with a printer who requires a maximum ink density of 240%. They've just kicked back a file with deep purple hues, with the explanation that it's "difficult" to keep a cover like this within that range.

What tools or windows do I look at in Photoshop to see where the problem areas are, or what other steps do I need to take as I attempt to revise this file to their standard? (In other words, I can't have the purples I want, but I'd like to change them only as much as needed. How can I know what I'm doing so that they won't kick back the file again, and charge me for another proof?) Sigh.

[Guest]

We just had a discussion about this a few months back.

It would be best if they gave you their profile for 240% ink limit.

You can go into color settings and under CMYK goto custom CMYK and make your own but I have been told that this is not the best and you are not customizing the previously chosen profile. If this is what the printer is referring to then you should be fine.

I would talk to the printer though and be sure.

[Chris Cox]

For most design purposes you "fix" it by working in RGB then converting to a CMYK profile that includes the desired maximum density setting at the very end.  (soft proofing along the way)   After you are in CMYK, it's not easy to correct (not if you want pure blacks to stay pure black).

Photoshop doesn't currently have any tools for showing you areas that exceed a certain ink density.  (it's on the requests list)   But the info palette does have a setting for showing ink density ("Total Ink").

People frequently make selective color or area corrections to ink density using simple adjustments (levels, curves, etc.).

[Zeno_Bokor]

open the Info Panel, set the readout to Total Ink and hover your mouse over the image to see your total ink (don't think that there's a way to show this value for the whole image at once). To reduce that value you could try using Curves and drag the whole curve down to reduce the contrast of the image and the total ink count with it

[Reynolds__Mark_]

1106design - there is a way to specify a total ink amount when converting to CMYK. Edit/Convert to Profile, choose Custom CMYK. Here you will find settigs for Total ink limit as well as black ink generation and "limit" - found nowhere else.

This method is not often recommended these days for "color management reasons" - but in practice for what you want it might work quite well.

Best method though is using Curves and controlling density this way - placing eyedroppers and reading total ink from the info panel. You need to first find what the highest density areas are, and place your points there.

[Guest]

Reynolds (Mark) wrote:

1106design - there is a way to specify a total ink amount when converting to CMYK. Edit/Convert to Profile, choose Custom CMYK. Here you will find settigs for Total ink limit as well as black ink generation and "limit" - found nowhere else.

This method is not often recommended these days for "color management reasons" - but in practice for what you want it might work quite well.

Nobody reads post one

[Reynolds__Mark_]

Just wasn't sure he should change to a custom CMYK, in Color Settings Buko. Could cause all sorts of problems, if they dont realise they got to change it back. Especially if its a low ink setting

[1106design]

Thanks for all the replies. Here's where I want to go screaming into the night. A solution seems possible, and then someone else writes that "all sorts of problems" can occur if I don't know I have to change it "back." Back to what???!!!

Unfortunately, I'm dealing with a printer who manufactures a million books a month, and am currently trapped in customer service hell where they are sending me boilerplate paragraphs that don't answer my questions.

Please, all, is consensus possible on what I should DO?

Thanks,
Michele

[Reynolds__Mark_]

Sorry, heres the full explanation (hopefully maybe others will chime in if ive missed anything)-

As Buko suggested in his first post ....you can change your Color settings to a Custom CMYK  (edit/color settings - permanent in Photoshop until you reset them )- this custom cmyk will allow you to specify a "maximum Ink". Then just converting to Cmyk any time Image/mode/CMYK - will convert using the setting you have created. In your case provided you chose  "Total Ink limit" 240% - It will not generate CMYK separations, where the total ink exceeds 240%

One problem with this -  you have to remember that its set this way, so that it can be set back to something more sensible as your default. On some presses a total ink of 240 will look very washed out, and flat. So alternatively you can also convert using the less dangerous method I suggested - Edit/Convert to Profile/ Custom CMYK - you can record this as an Action.

___________________

Lets say you have a CMYK file already and you need to change it to a lower ink coverage - the best way is using Chris' suggested method of using a Curve to lower ink density.  its more contollable. Heres how…

• Use a threshold adjustment layer to find out roughly where in your image the maximum ink coverage  is.

• Place eyedroppers at these points.

• Change the readings in info panel to show Total Ink.

• Now use your curves to lower overall density - paying special attention to your Black (k) channel - best practice to lower K channel separate to the rest of the image. This is because K channel holds most of the detail in the image.

[Guest]

This is why it is best to keep everything RGB until you are ready to convert to CMYK.

If the file is already CMYK you can convert to RGB then back to CMYK with the 240% limit.

[1106design]

THANK YOU, ALL!

I just used the Custom CMYK profile method, and checking the former dark areas with the eyedropper shows the total ink density to be within the 240 limit now. It didn't change the color too much on screen (I know that's not to be trusted).

One follow up question, when I convert the InDesign file using PDFx, do I have to change anything in the output dialog? I didn't, just now, but it looks like it's set to convert back to the old profile with the higher ink limit. Does that matter, as long as I've reduced the ink limit in the Photoshop file? It's not going to "add" ink, is it?

Thanks,
Michele

[Reynolds__Mark_]

PDFx Export settings - Output - No Color Conversion.

You don't want Indesign changing anything - if you are trying to control your CMYK output using Photoshop.

[1106design]

Thanks much!

M.

[Paul_Cutler]

If you can't get a profile from the printer, go with Curves.

In Photoshop there is always a few or more ways to do things.

pbc

[aprilk31527202]

How are you supposed to use the curves in Photoshop when you need to look at the overprint selection in InDesign to see what you are doing?

[aprilk31527202]

I have this issue too, and with a similarly colored file that is very temperamental when say, swapping ICC profiles, so I am not thinking that using an ICC to make the adjustment is the answer. - Also I did try that, and it didn't seem to work at all. InDesign still showed the same area as being overprinted at 240%.

To be honest, all of these "fixes" sound ridiculously impractical and finicky or very technical... likely accompanied by unwanted color adjustments and "be careful so that you can still revert your files"... Why in the world is this so complicated? In my case, I don't think the prints are turning out badly - I don't see any obvious bleeding even with what seems to be significant overprinting (> 240% < automatic standards - something around 300%)... So why mess with it? - Everyone is swearing that this is SO important, but is it really?

Are there any alternative solutions to this in general... like when printing in RGB or doing other things that aren't typically done? Do some printers work with higher density inks?

Thanks!

[D Fosse]

It's not complicated at all.

You need to get the appropriate CMYK profile from the printer. That's all there is to it.

Each CMYK profile corresponds to a specific printing process: an offset press calibrated to a certain standard, using certain inks on certain paper stock. The profile has the ink limit built in. You can't "experiment" with profiles - you need the correct one. Period.

[NB, colourmanagement net]

"with a similarly colored file that is very temperamental when say, swapping ICC profiles, so I am not thinking that using an ICC to make the adjustment is the answer."

you're right, it's not - hard to know what you mean by "swapping ICC profiles" but it doesn’t seem a good idea.

What you actually need is an ICC profile, specific the actual 'print condition', you'd get that from your printer. They may well specify an industry-standard profile like one of that GRACoL variant and that’s fine. But converting from RGB to the right CMYK is the way to control inklimits. 

And once converted don't go increasing saturation or pushing blacks - the CMYK profile does not restrain your post conversion editing activity to within the range of the print output. 

"Everyone is swearing that this is SO important, but is it really?"

YES

as an example, if you overdo the ink levels and the printers pre-press dep't don't spot it, you'll potentially get offset or even ink running on the paper. 

I hope this helps
neil barstow, colourmanagement net :: adobe forum volunteer:: co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management