Converting from CMYK to RGB (to work with it), then back to CMYK

I am trying to make designs for printable products (shirts, mugs, phone cases, …).
I heard about the issue of the RGB and CMYK colors when printing.
I am using Inkscape for my designs as it is a free, but it does not support CMYK colors.

I had an idea:

  1. Pick a CMYK color.
  2. Convert it to RGB.
  3. Working with this RGB color.
  4. When printed, the RGB color that came from CMYK will be converted back to the same original CMYK color.
  5. Then I get a color in print that is very close color to the original one, since CMYK color gamut is included in the RGB color gamut. So when I pick a color that can be found in the two gamuts in RGB, it will be the same when converted to CMYK.

Is this a good idea?

Or does anyone have alternative ideas on how to get similar colors when printing while the design is a PNG image with RGB colors ?

Answer

When printed, the RGB color that came from CMYK will be converted back to the same original CMYK color

Nop… It will not.

There are several reasons. Color profiles, changes in gamut, simulations on the screen…

But I will only address 1.

A CMYK value has 4 variables (C+M+Y+K). A given color can actually be created using a combination of inks, mainly what it is called chromatic and achromatic one.

When C+M+Y neutralize each other they produce gray, so this gray can be substituted with black ink at some percentage. Do you want to replace this gray completely with black? only half of it? 3/4, 1/4 1/10?

So there you go… You can have now, not only 2 ways of replacing one color but dozens of them.


The way you probably should go is taking one RGB chart. Here, have this one:

https://otake.com.mx/Color/RGB-01-Letter-LowRes.png

Import it on Scribus and take a look at how the colors are changed using some specific profiles… or If you can print the test chart on the same method you are going to use to print.

Attribution
Source : Link , Question Author : romaz2 , Answer Author : Rafael

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