Skip navigation
This discussion is archived

This Question is Not Answered

1 "correct" answer available (10 pts)
3,352 Views 5 Replies Last post: Mar 26, 2011 6:05 AM by lbrown RSS
Level 0 4 posts since
Feb 24, 2011
Currently Being Moderated

Mar 25, 2011 3:33 AM

How can I retain my RGB color when I switch to CMYK?

Hello All!  I'm a new author, and  I've just finished a full color childrens book. I've had some problems  with the proofs and CS recommended that I save the pdfs in CMYK. I can  do this but it's dulling the colors. I'm using Adobe PS CS5. How do I  retain my colors or brighten them up? Also when I formate, or save to  PDF, could someone help me with the best settings. My book size is 8X10,  and I'm having a little trouble finding the right paper size to make  sure I've got the right bleed, etc. Hey thanks in advance everyone.

 

Have a great day. Linda Brown

Level 5 14,268 posts since
Sep 5, 2009
Currently Being Moderated
1. Mar 25, 2011 6:04 AM in response to: lbrown
Re: How can I retain my RGB color when I switch to CMYK?

Color

Color perception is relative: colors are relative to each other (e.g. simultaneous contrast), what people see is relative to themselves (most people have some color deficiency).

 

In Photoshop you can, and should, look for out-of-gamut colors .  Adobe can mark these with the color of your choice.  You can see them and you can alter them or let the conversion from RGB to CMYK do it, example. (Out of gamut http://www.elijournals.com/premier/showArticle.asp?aid=27507)

 

I would recommend printing out your images. Your printer is most likely CMYK. Use a matte photo paper. Then compare the proof to them. This is still not a fair comparison, because the paper, inks, and process are different between your printer and CS's printed page. But you can make relative adjustment at your end and get a sense of where they will go when CS prints them.)

 

As a practical matter most commonly, the out of gamut colors in RGB tend to be very bright and saturated.  However: what are you comparing? If it is the monitor RGB and a printed proofs? You are now comparing three things:

 

Every color book printed CMYK (by CS or any color printer) has the same RGB to CMYK issues.  You further exacerbate the issue if you are comparing the RGB on your monitor to the CMYK of a printed piece.  However, I have printed two color art books with CS where all the images were created in the computer (RGB) http://12on14.com/pages/print_test_1-24.pdf.  I can say that the printed version compared to the computer original are dead on (the scans of the printed pieces have Moiré patterns that alter the color, which I did not correct for in this PDF). There are color books printed with special colors, (my Epson 7600, prints CcMmYKk), and often 6 or more colors--this sort of printing is generally rare. For example, CMYK might be substituted with BMYK or CBMYK.  Sometimes not only adding process blue (not cyan) a red, in addition to magenta.

 

Unfortunately all the color examples I've linked to are RGB examples trying to show the difference between RGB and CMYK.  One of the examples, (Color space http://en.wikipedia.org/wiki/Color_space  ) appears to have been generated simply by putting a film over one side of the color model, if color were consistently and perceptually that far off, most color books would be a disappointment.)

 

Take a look at General Illusions: http://www.michaelbach.de/ot/. Fortunately, CMYK is an illusion (so is RGB) and if it is seen by itself it works--that is, color is relative, and what you see on the printed page does not come with a RGB comparison.  To further add to the fun, most people have some color blindness (PIP color test http://colorvisiontesting.com/ishihara.htm -- a friend of mine administered the complete test to the employees of his color photo lab, no one, including him, could see 100% of the test pages.)

 

The test I used when approving press sheets was this: does it look believable?  (Not, does it match the original art?)

 

PDF

Your PDF should be made with the PDF/X-1a preset if that is available, and if you can use Acrobat Pro, so much the better. However, lots of people use 3rd party conversion programs to generate their cover art (OpenOffice, which uses PDF/A, or doPDF, cutePDF, pdf995 etc.) and don't have problems. In the Help window (upper right, not the Guidelines/FAQs), type in "PDF," there is a section, I think the first one that will list all the specific settings CS wants, but PDF/X-1a will take care of that for you.

 

Size

An 8 x 10 size page with bleeds is 8.125" x 10.25", depending on what happens on the spreads, some people use 8.25" x 10.25". You'll have to describe your project for better advice.

 

 

Walton

Mechanics & Punctuation free, 20 page guide to everything punctuation Build Your Book free 98 page guide to designing your book Contact for graphics, design, and typesetting help  GIMP tutorials, GIMP, GIMP Help, excerpts from GIMP Supremacy 

Level 5 14,268 posts since
Sep 5, 2009
Currently Being Moderated
3. Mar 25, 2011 4:47 PM in response to: lbrown
Re: How can I retain my RGB color when I switch to CMYK?

This means nothing (although you can see some of my art here) because everybody's work is different, but I often go back and forth from RGB to LAB or CMYK to handle specific kinds of color corrections and adjustments.  Since my work is intended to be printed (not projected: website, monitor images, slide projector), CMYK is ultimately the color mode things will be in (whether they are screened, as in a CS book, or printed with a stochastic dot by my inkjet printer).  So from my point of view, nothing is lost going to CMYK because that's where things are headed anyway.

 

I hope I helped.

 

Walton

Mechanics & Punctuation free, 20 page guide to everything punctuation Build Your Book free 98 page guide to designing your book Contact for graphics, design, and typesetting help  GIMP tutorials, GIMP, GIMP Help, excerpts from GIMP Supremacy

Level 5 9,278 posts since
Aug 22, 2008
Currently Being Moderated
4. Mar 25, 2011 8:53 PM in response to: lbrown
Re: How can I retain my RGB color when I switch to CMYK?

As walton mentioned, it's not uncommon to produce colors in RGB that don't translate well to CMYK.  With Photoshop, you can click View > Gamut Warning to highlight out-of-gamut color problems.

 

As already noted, working in CMYK to begin with and using the PDF/X-1a preset is probably the best approach to preparing color images for print.  However, if you must work with images in RGB and are losing a lot of in-gamut colors when they're converted to CMYK, you might try assigning/applying the ICC color profile to the image, and then tagging everything for color management when creating the PDF.  This may not be as color-consistent from book to book as when all colors are converted to CMYK up front, but the variances seemed relatively minor in the test booklets I did this way.

 

Hope that helps.  Best wishes.

Actions

More Like This

  • Retrieving data ...