Working exclusively in RGB for Internet and Press

[Seamus]

So a CMYK document is set up in InDesign according to a print shop profile; the RGB images are graded in Photoshop by being soft-proofed using the print shop's CMYK profile; then the images are placed in InDesign but remain RGB; while exporting to PDF, the images are converted to the CMYK profile of the print shop.
That's the print version of the book taken care of.

Because the images are in RGB in InDesign, the book may also be exported as an RGB PDF file.
That's the eBook for the internet or any electronic device.

I'm just wondering...

1. Since the RGB images are 'tailored' for the CMYK profile, are they not perhaps too 'bright' or even 'off balance' for the eBook?
Will they not have to be regraded back to their original 'look', ie pre soft-proofing, to look right?

2. Again, since the RGB images are soft-proofed for a specific print shop's CMYK profile, if later the book is to be printed by another print shop with another CMYK profile, won't the RGB images need to be soft-proofed again, essentially changed?

3. Perhaps the workaround is to keep the pre soft-proofed versions of the RGB images intact (these would also be the eBook versions). And have soft-proofed versions for every print shop profile?

4. Is it possible, given that we have excellent RGB to CMYK print shop conversion software, such as GMG Colorserver, that we can work exclusively with RGB images, taking care not to have colours that are very out of gamut with CMYK (using 'conservative' soft-proofing)? So we don't need to keep soft-proofing for different print shops? The same RGB images then work for the eBook and the printed version.

This would save a lot of work!

?

[Damien Symonds]

3 minutes ago, Seamus said:

1. Since the RGB images are 'tailored' for the CMYK profile, are they not perhaps too 'bright'

No.  If anything, the opposite will be true.  When soft-proofing for press printing it's most common to have to dull some very vivid colours of the RGB file to fit into the CMKY gamut.  (In fact, this is true for RGB printing as well - did you see this thread?)

5 minutes ago, Seamus said:

or even 'off balance' for the eBook?

No, definitely not.  (As long as the soft-proofing and related adjustments are done properly, of course.) The balance will be fine.  It's just that some colours might be a little duller by necessity.

6 minutes ago, Seamus said:

Will they not have to be regraded back to their original 'look', ie pre soft-proofing, to look right?

Yes, it wouldn't be too much trouble at all to put this simple extra step into your workflow, if you felt it was necessary.

But heck, I wouldn't bother.  For the small percentage of photos that would be affected, it's not worth it.

7 minutes ago, Seamus said:

2. Again, since the RGB images are soft-proofed for a specific print shop's CMYK profile, if later the book is to be printed by another print shop with another CMYK profile, won't the RGB images need to be soft-proofed again, essentially changed?

Alas, yes.

Again, though, it's only for a small percentage of images (ones with very vivid colours, eg flowers.)

8 minutes ago, Seamus said:

3. Perhaps the workaround is to keep the pre soft-proofed versions of the RGB images intact (these would also be the eBook versions). And have soft-proofed versions for every print shop profile?

Not exactly.  You would only have one file - the PSD file - with a specific Hue/Saturation layer for each print shop, which you applied in accordance with that shop's soft-proofing profile.  Then for each print job you'd turn on the necessary layer, and turn the others off.

(In case I haven't already mentioned this, the photos you put in the InDesign document are always PSD files.  Never jpegs.)

10 minutes ago, Seamus said:

4. Is it possible, given that we have excellent RGB to CMYK print shop conversion software, such as GMG Colorserver, that we can work exclusively with RGB images, taking care not to have colours that are very out of gamut with CMYK (using 'conservative' soft-proofing)? So we don't need to keep soft-proofing for different print shops? The same RGB images then work for the eBook and the printed version.

This would save a lot of work!

I agree.  It would be wise to do a bit of testing to make sure you had a good system in place, but yes, it sure would save a lot of work.

Is this something you're going to be dealing with a lot?  Printing the same images at various print places?

[Seamus]

Hi Damien. Thanks for those in depth answers.

I've found a print shop that uses GMG Colorserver (the same place that printed the 'Kevin - My Memories' book nice and bright (remember, the book that was printed really dark by another printer?). In questioning their process for further print jobs they suggested that their GMG RGB to CMYK conversion would probably do a better job than my own conversion. And reading up on GMG Colorserver, for proofing and printing digital and litho, it seems to be very clever and moving away in some sense from ICC profiles. Like it can 'see' the colour/brightness the original file intends and recreate it very accurately in CMYK. Almost like a home desktop printer can do.

What I'll do is make up a series of tests and send on to them for proofing, as you suggest.

I get books from people compiled in Word and OpenOffice, essentially in RGB, and the writers have no notion about CMYK (or RGB for that matter), but their monitors are decently graded. They want an eBook and a printed version. So, I'm looking for a simple, but high quality, solution.

16 minutes ago, Damien Symonds said:

Is this something you're going to be dealing with a lot?  Printing the same images at various print places?

No, I plan to stick with the GMG people. However, your answers will certainly help me in case I have to deal with a print shop with less forgiving printing software.

[Damien Symonds]

9 hours ago, Seamus said:

Almost like a home desktop printer can do.

Can you elaborate on this strange statement?

[Seamus]

Hi Damien. Yes, it seems some digital presses are capable of producing wide gamut prints. Here’s a quote "Digital printers look a lot like giant versions of the printer you have in your house." from this article... https://www.printingforless.com/blog/printing/guide-to-using-color-and-ink-in-commercial-printing/

Another quote from the same article... "Because they’re not just working from four plates, digital presses support the wider and more vibrant color gamut of RGB images – finally ending the RGB vs CMYK debate."

Quite the statement, and I’m sure some digital presses are better at it than others. I’ll contact my new-found 'good printer' and see what they have to say about it.

[Damien Symonds]

Sorry, I wasn't clear.  I was more interested in this section.

On 9/21/2020 at 8:40 PM, Seamus said:

it can 'see' the colour/brightness the original file intends and recreate it very accurately in CMYK.

I don't see how you correlate that to a home printer.

[Seamus]

Sorry, my strange way of trying to understand the inner workings of printers! ?

[Damien Symonds]

I assure you, a home printer has no such cleverness.  It prints a rough approximation of the file you send it, within its limitations.