I tried to understand it on this article but couldn't understand it. I'm observing this for couple of years but never really thought about it much.

Also, sometimes when I'm working on something using gradient, colors for gradient stops turns black and white no matter which color I choose. So one day, I accidently clicked on this Registration mark, it filled black to my shape (why?) and again filled gradient colors and it was no more black and white. I really don't understand what trick it did.

enter image description here

So what is it and where can we use it? I have never intended to use it or felt the need. How useful/common is it among designers?

For me, the question claiming to be duplicate, isn't. The question answers there don't specifically focus on explaining what the registration mark is. Also, there's another doubt which I've already added in my details. I'm not familiar with InDesign, that may also be reason I'm not able to perceive those answers properly.

  • @AndrewH unfortunately no. I already had searched it before asking it. I have additional doubt too mentioned in details. Further I feel that InDesign answers don't talk specifically about my problem.
    – Vikas
    Mar 23, 2021 at 13:46
  • Registration marks are used for lining up the separations when using printing machines. They're only useful in print. Check the Print Registration article on wikipedia if you want to get more in-depth information.
    – Billy Kerr
    Mar 23, 2021 at 17:27
  • I really don't understand why it's closed. I really can't understand those 2 answers there. They are bit advanced for me :(
    – Vikas
    Mar 23, 2021 at 17:28
  • Simply put... the Registration swatch is only to be used when you are manually creating trim, bleed, or die marks (i.e printer marks) ... or... when you want "black" on a mask (In Illustrator, that means on Opacity Masks in a CMYK document) -- Other than these two uses, ignore the swatch entirely and never use it for general artwork.
    – Scott
    Mar 23, 2021 at 17:41
  • 1
    I updated my answer on that question as well Vikas.
    – Scott
    Mar 23, 2021 at 17:50

1 Answer 1


Registration is 100% of all inks. It is a swatch that you want to avoid using as much as possible when making print, because it may easily render your cPDF invalid for print. It gets used in eg. packaging design to draw crop marks for custom package shapes (other than rectangular).

Your issue with the gradient stops may be that there are buggy situations in Illustrator where the software leaves a gradient in grayscale, until you drag in a swatch that use other inks than black. Registration is such a swatch: it uses all available inks.

That's the short answer.

The longer answer is pretty technical.

In regular four-colour printing, colours are created by mixing different coverage of the four main colours Cyan, Magenta, Yellow and blacK (or Key). Some elements on the cPDF are printed in 100% of all colours, to make sure they always show up on the final product, even if one or two of the inks go missing during the print. The elements I'm talking about are the printer's marks you inlcude when creating a cPDF: crop marks, colour bars, page information et cetera.

So Registration is a colour with the CMYK colour composition 100/100/100/100. If you happen to add more inks (a Pantone ink, for example), it becomes even more: 100/100/100/100/100; C/M/Y/K/Pantone.

Ink is a liquid. Paper is, well, paper. Paper doesn't react well to liquid. There is two scenarios when you use too much ink (read: if you make your paper too wet) that may happen in print, both disastrous.

In the case of uncoated paper, the paper will absorb the ink you spray on it. If you make the paper too wet (read: if you use too much ink), the paper's structure will weaken because it gets wet. This may cause the paper to tear during the printing process, which is a nightmare for the printer. They'll have to halt the print job, clean the press of any debris, and restart.

In the case of coated paper, the ink stays on top of the coating as a liquid film. If you use too much ink, that film will still be wet when the next copy gets put on top of the first. This will create very ugly stains in the final product.

For this reason, each kind of paper has a maximum cumulative ink percentage. That is jargon for 'all ink percentages added together'. In case of most default paper, that maximum ink percentage is around 280%. It's lower in case of newspaper print (which is uncoated and very thin and may be a big higher for thicker, uncoated papers. No colour that will end up on the final product (after cropping) can have more than that total percentage of ink.

Registration is 400% of ink, well above that limit. Hence, it should not be used in your design. Never use registration as an actual colour in your artwork.

There are techniques that use Registration in other ways, as this answer on a related question shows.

  • when we say "Registration is mainly used to draw crop marks". I don't get it. You mean when we enable print/crop marks in illustrator while exporting, there's option to change marks to Registration black?
    – Vikas
    Apr 2, 2021 at 9:57
  • @Vikas No. But there are times when you need to draw crop marks manually, for example in laying out a cardboard display box that needs to be custom-cut and folded. In that case, you'd draw crop marks yourself, in Registration.
    – Vincent
    Apr 2, 2021 at 10:09
  • I just can't get this. "draw crop marks yourself", "manually".
    – Vikas
    Apr 2, 2021 at 10:11
  • @Vikas Well, draw some lines in Illustrator, at the edges of the working area, to indicate where the cropping edge should be?
    – Vincent
    Apr 2, 2021 at 10:13
  • okay, but you said if we use it in our file, cPDF might be invalid?
    – Vikas
    Apr 2, 2021 at 10:19

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