CMYK from the start vs RGB >CMYK on Export

[brunoczech]

Hi guys,

I am sorry but I will probably never understand the color management...

I believe the proper way for print is to create the file in CMYK/FOGRA39 from the beginning and then send it for print as such.

What happens when the file is created as RGB/sRGB and then sent to print in CMYK/FOGRA39?

See the attached files - the RGB_print was created as the latter and CMYK_print file as the former one.

Which one will come out right from print? I'm just sending it over to the printer and will have results sometime next week.

I know that CMYK colors look different on display but what surprises me is how much different is the first logo's color. There isn't such difference within the second logo, so what gives?

The original RGB/HEX colors were properly converted using online converters and I've checked like ten of them to make sure the conversion to CMYK was right.

 

 

 

agri_novitim_color_test_CMYK_print.pdf agri_novitim_color_test_RGB_print.pdf agri_novitim_color_test_RGB_RGB.pdf

[R C-R]

The short version of what gives is displays & printouts create color images in completely different ways, the first by producing light & the second by absorbing light from external sources. So at best, the onscreen display will create only a simulation of what a printed page will look like when lit by some specific kind of light source.

Moreover, because there are several different printing technologies that use different combinations of ink & paper (or equivalent media types) there can be no one 'proper' simulation or conversion that works for all of them. This is why to get predictable results hard and/or soft proofing is needed for each combination.

Of course, there is really much more to it than that.

[brunoczech]

Thanks for the reply.

I am aware of most of the facts you mentioned - but I've never seen such a big difference between RGB and CMYK on display. If you check the second logo - here the colours are much more similar than with the first one.

I've been sending files to print as CMYK/FOGRA39 for months now and never seen such different colours.

I have to wait for the results from the printer and I am really curious to see them, actually.

 

[lepr]

20 hours ago, brunoczech said:

The original RGB/HEX colors were properly converted using online converters and I've checked like ten of them to make sure the conversion to CMYK was right.

The online converters that convert #00AAAD to C100M2Y0K32 use a simplistic formula that takes no consideration of colour profiles, and they are useless for your problem of specifying colours for print.

[brunoczech]

9 hours ago, anon2 said:

The online converters that convert #00AAAD to C100M2Y0K32 use a simplistic formula that takes no consideration of colour profiles, and they are useless for your problem of specifying colours for print.

Would you recommend a proper converter for CMYK/FOGRA39, please? 

I mean for the times when it's not possible to get a printed proof in advance.

Thanks.

[brunoczech]

Well, the prints are back and it's exactly how I expected. The colour are totally different. Check the photos. 

How is it possible that orange, green and that light yellow colours are so very similar on both prints and the blue/green colour isn't? BTW these three colours look almost exactly like this on display, too.

They were all converted from RGB/HEX to CMYK using the same converter and yet they look completely different!

Same applies for the files in Publisher - if I create a new files straight in CMYK/FOGRA39, this particular colour #00AAAD when set up in CMYK looks nothing like it's supposed to. Not even on display, let alone print.

When the file is created as RGB/sRGB and then exported as PDF in CMYK, the colour is exactly right as it was meant to be in a first place. Which can be seen on the photo IMG_0264.

 

Now I don't know if I should give clients colour codes made by converter (CMYK 100 2 0 32) or codes that Publisher shows when working in RGB (CMYK 76 13 39 0).

 

Any ideas?

Thanks.

 

[brunoczech]

8 minutes ago, BofG said:

This is going to sound harsh, so I apologise in advance, but the truth is you need to do some reading on the topic of colour management.

😁 You're definitely right and I did read many topics. But I have to be honest - there is a chance I will never properly get this.

I've created lot of files in the last year or so - both in Illustrator, InDesign, Designer and Publisher.

When creating files for print I always used the same settings CMYK/FOGRA39 right from the start. Always exported properly, too. And I've never encountered any problems and I never got files back from the printer or the client due to the wrong colour settings. And - the colours on the screen and then in print were very very similar in each time.

This is the first and so far the only instance when I see such massive difference in colours on the screen and on the paper. Yes, I know the colours will never look the same on display and on print but they should look very similar, that's the point, right?

Would you mind sharing some colour management topic which would help me understand this more or preferably would you share your own way how to deal with this particular file?

Thank you for help!

[wonderings]

In many cases RGB converted to CMYK will show no differences, in some cases there will be HUGE noticeable differences. This is why I always start by converting any graphics/images to CMYK. Make adjustments at the beginning before I even get into the design/setup stage. Going through everything in RGB and then converting it at the end could lead to some unhappy results and a lot of wasted time.

[Belifant]

you did correct with the RGB_print file. That would have printed fine. It correctly converted from RGB to CYMK.

The reason your CYMK_print file came out all wrong is because you entered completely wrong CMYK values. Just do as you did already, upon export, chose CMYK as the output for the pdf, and it will get you closest to what is possible in CMYK.

You have to remember one thing: there is not the one exact CMYK. There are many many different CMYK profiles out there, all producing different values. 

Are you in Europe? If you print in Europe, the Fogra39 is not really the correct one. I suggest downloading the ISO_coated_v2_300%.icc profile, it is probably the safest bet for printing in Europe.