In InDesign what settings give the most realistic preview of a CMYK document (no spots)

[MarieMeyer]

In InDesign what settings give the most realistic preview of a CMYK document. I know there is no substitute for a proper printed proof, but I need to get as close as I can on-screen for now. I don't have any spot colors, and I have my destination CMYK ICC profile installed in the color settings. Is "Overprint Preview" still the best option? Or is that only for use when spots are involved?

[rob day]

I don't have any spot colors, and I have my destination CMYK ICC profile installed in the color settings.

The profile you set in Color Settings isn't necessarily the document's CMYK profile. Check that the assigned profile is correct under Edit>Assign Profiles it could be different than the Color Setting's Working CMYK profile.

The accuracy of the preview of CMYK color depend on two profiles, the assigned document CMYK profile and your monitor profile which is set by the OS during a monitor calibration.

Overprint preview forces any RGB or Lab colors to preview as they will output to CMYK, and would also show the effect of overprinting CMYK colors. OP should not change the appearance of CMYK color that is not overprinting another color.

[Willi Adelberger]

You need to choose the profile the printer needs for output. For raster images keep them in RGB and convert them if necessary not before export to PDF.

[Laubender]

Hi Marie,

FWIW: Separation results could be different of placed RGB images where reduced opacity is used within the image ( e.g. a layer option with PhotoShop is used ) in comparison to opacity effects applied by InDesign's Effects panel applied to a not transparent RGB image.

Below an example that is demonstrating this.
The same PhotoShop image with three layers placed three times.

The PhotoShop layers from top to bottom:
Layer 1: Opacity 100% showing a gradient
Layer 2: Opacity 50% showing the same gradient

Layer 3: Background Layer with fill color RGB 255|255|255 ( a "white" )

Now the image is placed 3 times on an InDesign page.

See screenshots from my German InDesign below.

Case 1 on top: All 3 layers are turned on. No effective opacity is visible.

Case 2 below: Exactly as case 1 with one difference:
An effect from InDesign's Effects panel is applied:

Opacity is reduced to 50 %

Case 3 at the bottom of the page:

Layer 1 is turned off. In effect you see the gradient of layer 2 with opacity 50% on the background layer that is filled with white.

Perhaps you would expect that 2. and 3. will lead to the same separation?

Apparently that's not the case.

Image of case 2 selected, Separation Preview on:

Image of case 3 selected, Separation Preview on:

So be careful what you are doing with effects on InDesign objects on the page.
The separation result of case 3 is much better than the one of case 2.

If you can, avoid RGB colors for text and vector objects in InDesign.

At least avoid tints on RGB swatches. You'd see the same separation values like in our case 2 that are not optimal. *

RGB fills that are not touched by InDesign effects and do not come with tints will separate as expected when output to PDF/X.

That goes for exported PDF/X-1 and PDF/X-4 alike.

* EDIT: CORRECTION
As long as you do not convert RGB swatches that are using tints to CMYK with InDesign's Swatches panel they will separate ok using PDF/X-1a or PDF/X-4.
Do the task of separation always by exporting to PDF. Or export RGB with PDF/X-4 so that the print service provider can do the separation.

The problem with applied InDesign effects on RGB images or objects with RGB fills cannot be avoided, I think.

Regards,
Uwe

[rob day]

Uwe, try setting your transparency blend space to RGB. In that case I get a match both in appearance and separation numbers.

Photoshop doesn't have the challenge of dealing with multiple color spaces on a single page when transparency is applied. The blend space in Photoshop would be the mode of the document—RGB in your example.

CMYK blend space

RGB blend space

[Laubender]

https://forums.adobe.com/people/rob+day  wrote

Uwe, try setting your transparency blend space to RGB. In that case I get a match both in appearance and separation numbers. …

Hi Rob,

I tried that, but unfortunately changing the blend space to RGB was no success.
Here a link to my samples where I also tried different things with RGB based spot and process colors and L*a*b* based spot and process colors. Transparency applied with InDesign's Effects panel would still be a problem to me:

Dropbox - Gradient-3-Layers-sRGB-PLACED-CC-2017.1.zip

( Perhaps we should discuss this in a different thread… )

Thanks,
Uwe

[rob day]

( Perhaps we should discuss this in a different thread… )

I think so.

I can see the problem in 2017 and it looks like a significant bug to me. I saved your 2017 test file as an .IDML and opened it into CC2014 and there the blending spaces work as expected. Over in 2017 it looks like the blend space gets stuck on CMYK. 2017 and 2014 are producing different separation values for the same files.

Here's your file dropped back to 2014 with the blend space as RGB and you can see that the blends match both in appearance and output numbers. I agree this is not happening over in 2017.

Sep values for ID version

Sep values for the PS version

[Laubender]

Hi Rob,
I did a new thread where I am discussing RGB with InDesign and the bug we are seeing with Transparency Blend Space set to RGB here:

Working with RGB | CS6—CC2014.2 vs CC2015.4—CC2017.1 | substantial bug?

To all others reading this:
Please, let's keep the two threads separate.

Marie's problem revolves more around CMYK and my thread is talking RGB and the mentioned bug with CC 2015 and above.

Thanks,
Uwe

[rob day]

Also, I can replicate the InDesign blend space effect over in Photoshop if I convert the transparent blend to CMYK. Checking the Flatten Image to Preserve Appearance in the Convert to Profile dialog gives me the equivalent of InDesign's RGB transparency blend space setting, while unchecking gives me the CMYK blend space result.

[Frans v.d. Geest]

If you do not have a Wide Gamut and calibrated and profiled display to judge it on, this is a bit of a mute topic...

[rob day]

It's true many CMYK spaces have some colors (generally limited to the 90%-100% cyan range) that are outside of most RGB monitor gamuts and those colors can not be properly displayed. So if your destination profile is a coated profile like Coated GRACol 2006, you might not be able to rely on the display's soft proof for saturated cyans and blues (for smaller CMYK gamuts, i.e., GRACol Uncoated it would be less of a problem), but the rest of the CMYK gamut could be accurately soft proofed with the correct profiles.

I don't think the CMYK soft proof of the RGB colors in Uwe's example would get clipped by a typical display's gamut, but the choice of the Transparency Blend Space would affect both the displayed CMYK soft proof and the CMYK output numbers showing in Separation Preview.

I get the feeling that Marie's question is limited to the display of native CMYK swatches and colors, and is not a broader color management question. So you are right, she should not rely on the soft proof for saturated cyans, but the accuracy of her monitor profile and the document's CMYK profile will still be important for displaying the rest of the CMYK gamut.

[Laubender]

Hi Rob and Frans,
Marie said: "In InDesign what settings give the most realistic preview of a CMYK document."

So yes, we talking CMYK only.

Now a reasonable question could be:

Did Marie place CMYK images with different ICC profiles? Different to the document's separation color space?
And what is the policy to that situation when exporting to:

A. PDF/X-1a => You have to convert to the document CMYK color space.

Marie in principle is able to simulate the results with InDesign. In the limits of her monitor's gamut and the quality of calibration.

B. PDF/X-4 => Put conversion to CMYK into the hands and knowledge of the print service provider.
If the print service provider is doing the job very good and is e.g. using Device Link technology to get an "optimal" conversion result, Marie would never be able to simulate the results with InDesign. Even if her display is perfectly calibrated and able to show a reasonable CMYK gamut. InDesign is not supporting Device Link profiles.

Regards,
Uwe

[Laubender]

MarieMeyer  wrote

… Is "Overprint Preview" still the best option? Or is that only for use when spots are involved?

Hi Marie,

best use Separation Preview turned on.
Overprint preview is automatically activated with that.

In case of spot colors:
For previewing L*a*b* spots to CMYK separations correctly, I think you have to use Separation Preview.
Overprint Preview alone would not be good enough. Also check your Ink Manager settings about spots and the conversion policy.

Regards,
Uwe