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Best Pre Press Workflow


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I've produced a few books in the past few years and, as technology rapidly changes, am now wondering what is the best way to prepare graphics for my next book project.  I read on the internet, and I glean from talking with experienced people in the business, a variety of approaches.  These are the solutions I have come across...

'Work in RGB and let the press people do the conversion to CMYK.  Modern presses do it better than you ever could with your software package.'

'Work in RGB, soft-proofing in the CMYK profile that the press uses.  Export your PDF as CMYK, embedding that profile.  The PDF export does the conversion.'

'Work in CMYK using the profile that the press uses.  Convert your images to CMYK as you work in your document.  Export your PDF using Native color space.'

I'm sure there are other approaches.  For example, what if an eBook is to be produced as well as going to print?

I'd appreciate any insight!

Seamus

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Unfortunately it's more than two decades since I used CorelDraw.  So all I can do is tell you how it works in InDesign, and hope it translates ok.

In InDesign we set up our document in the CMYK profile that the print shop advises for the job (make sure they DO advise one, don't just guess).  It's vitally important that the document is CMYK, not RGB, so that blacks are accurate.  We do our design - text and linework and graphs and whatever else - in that CMYK document.

For photos, we edit them in Photoshop and leave them in RGB mode, but we soft-proof them as you mentioned above, and make any adjustments that are necessary.  We DON'T convert them to CMYK.

We place the RGB photos into the CMYK document.

Then, as you said, the PDF conversion makes the photos CMYK during the output process.

10 hours ago, Seamus said:

what if an eBook is to be produced as well as going to print?

This is one of the reasons we do it as described above.  If your final PDF output is an RGB e-book, the photos stay exactly as they are, and the other items get converted to RGB.

This means that no matter what you're outputting, none of the elements of your design get converted more than once.  Multiple colour mode conversions are very dangerous.  There is no "round trip" in colour conversion.  If a photo is in RGB, then gets converted to CMYK then back to RGB again, the values don't end up back where they were.  They'll be different.  This must be avoided.

Gosh I hope this makes sense.

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Hi Damien,

Thanks for that.

I compiled a book recently that didn’t print well, though the PDF CMYK file going to the printer looked fine.
This was my workflow...
Document RGB (in CorelDraw black text is automatically set as 0, 0, 0, 100 CMYK)
Soft-proofing in CMYK FOGRA 39 (same as press house)
Images, after soft-proof, converted to CMYK and placed in document
In PDF, objects exported as CMYK, profile embedded

The eBook was done first, hence the reason for the document being RGB to start with.  Perhaps this was the cause of the dark print, because you say above It's vitally important that the document is CMYK, not RGB, so that blacks are accurate.

All along, I've thought the images were the problem, but it’s the document?  Does exporting all objects, which includes text, I presume) not change the document to CMYK?

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Hi Damien. I've used the X-Rite to calibrate my Viewsonic VP2468 using the 3D LUTs that are 'embedded' in the monitor.  I don't know if your instructions cover that usage but I'll certainly have a look.  I have other monitors as well (minus 3D LUTs) that I regularly calibrate.  Interesting, your comment about having actual correct prints beside you!  Makes perfect sense, really!  I'll read through the directions.  Thanks!

 

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I print Cards, Framed Photos and CD covers.  They look very nice in every way, but I wouldn't call them high end!  For colour management, I basically work in sRGB (monitor calibrated to that), then I let the printer do the printing (as opposed to using a special printer profile), since my printers - Epson ET2500 (tweaked a little to take down the red) and Epson R1800 use sRGB anyway.  Works surprisingly well.

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15 hours ago, Seamus said:

The eBook was done first, hence the reason for the document being RGB to start with.  Perhaps this was the cause of the dark print

Unexpectedly dark printing is first and foremost the result of a too-bright screen.  What luminance target do you calibrate to?

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I can't remember the target luminance last time I calibrated, but I see that my current user profile is at 120 nits. Seems high, but the room is fairly bright. I see your recommendation is 100 nits. I'll have a look at all that again in my next calibration.

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On 9/14/2020 at 5:06 PM, Seamus said:

I compiled a book recently that didn’t print well, though the PDF CMYK file going to the printer looked fine.

This was my workflow...
Document RGB (in CorelDraw black text is automatically set as 0, 0, 0, 100 CMYK)
Soft-proofing in CMYK FOGRA 39 (same as press house)
Images, after soft-proof, converted to CMYK and placed in document
In PDF, objects exported as CMYK, profile embedded

The eBook was done first, hence the reason for the document being RGB to start with.  Perhaps this was the cause of the dark print, because you say above It's vitally important that the document is CMYK, not RGB, so that blacks are accurate.

All along, I've thought the images were the problem, but it’s the document?  Does exporting all objects, which includes text, I presume) not change the document to CMYK?

I was wondering if you could send me both the ebook and the print PDF to take a look at?  https://spaces.hightail.com/uplink/BellePhotography

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Hi Damien,

The eBook and print PDF are a different size in that the eBook is A5 size and the printed book was made as a Coffee Table book, ie much bigger in size. All the images had to be made bigger, etc. and converted to CMYK.

I'll be interested in what you have to say. They're uploading as I'm writing this.

Some of the images are a tad blurry because they were scanned from old blurry photos to start with.

I've attached two sample images here of how the book was actually printed.

Thanks for your help with this!

Seamus

Image 1 Printed.jpg

Image 2 Printed.jpg

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While it's true that there are a lot of dark photos in the book (mostly the old ones) the two that you posted above aren't dark at all.  I see absolutely no reason why they would have printed dark.

There can only be two reasons, I figure.  Either (a) it was just a bad print job, or (b) they shouldn't be using FOGRA39.

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