How do I adjust dot gain?

[Amadís]

Hi, a newspaper has asked me to adjust an illustration to allow a 30% dot gain. While I understand what this means and I know it has to do with colour profile presets, I don't know how to address the request. Is it possible to do this without leaving Illustrator or should I go into Photoshop? The image has no photos. Also, they are requesting not to exceed a 230% ink weight, and I am completely lost in this last part.

[Doug A Roberts]

Amadís  wrote

Also, they are requesting not to exceed a 230% ink weight, and I am completely lost in this last part.

I am by no means a print expert, but this part means the combined values of CMYK should not exceed 230% (i.e. 100C + 30M + 30Y + 0K = 160% ink weight).

[Amadís]

Thank you, Doug! That was very helpful.

[Monika Gause]

You can achieve this by converting your artwork into an appropriate color profile when exporting it to PDF. In order to work well, this of course requires that your color management is set up accordingly.

BUT: your artwork most probably is designed in CMYK (since you will be printing it). An ICC-profile based conversion from CMYK to CMYK will wreck your blacks and make them muddy.

What kind of design are we talking about?

[Amadís]

Thank you for replying, Monika. The design has no real black, but I'll have to adjust the darker shade. Is there a way to precisely observe the percentage the newspaper requests? If not, which colour profile should I choose?

[Monika Gause]

In the case of this simple artwork with the limited number of colors I wouldn't do a profile conversion. Apart from that: Only the newspaper can tell you which profile they use or recommend.

I'd rather Select all and then use Edit > Colors > Recolor artwork

You can target each of the resulting colors and then enter the values precisely. The 30% dot gain will make them darker. In order to be able to somehow predict the result, printed newspaper samples would be useful. They exist in books such as this one (first search result, just a sample, so you know what I'm talking about) https://www.amazon.de/DCS®-Book-HKS-RAL-3-0/dp/B000A0K2L2/

You could also try and set a softproof profile in View > Proof setup. The Dot Gain profile there is a grayscale profile. So it would be best to ask the newspaper which one they recommend or use.

[Amadís]

The newspaper sent me a PDF with no colour profile specification. Is there no tool to calculate this precisely?

[Danny Whitehead.]

They really ought to be supplying, or at least recommending an appropriate ICC profile, but if you've asked them and they won't, then Stephen has recommended some good industry standard ones.

Personally, I'd do the 'your CMYK' - RGB - 'Newspaper CMYK' conversion in Illustrator, then fix the black-plate-only elements after, as there's only a small amount.

[Amadís]

Thanks for the tip. There is no black in the art boar. Do I still need to adjust it?

[Stephen Marsh]

Further to Monika's reply, I would create a copy of the original file and tile them both on the monitor so that you can view both at the same time. I would then assign an appropriate newspaper profile to the copy, then adjust the colours as mentioned by Monika to be visually similar (you will be lightening tones that are less than 100%).

As previously mentioned, the alternative would be to again work on a copy, change the document colour mode to RGB, then make a temporary colour settings change to the appropriate CMYK work space profile, then change document colour mode to CMYK and adjust as required (don't forget to change the colour settings back to the original colour profile).

[Amadís]

Thank you Stephen. Would going back and forth with colour modes solve the problem? I did not understand that part. What would an appropriate newspaper profile be? I realise I can just lighten all colours to somewhat compensate for dot gain, but I’d like to do it precisely.

[Stephen Marsh]

A "US Newsprint (Snap 2007)" ICC profile ships with Adobe apps.

SNAP 2007

Or for an international specification:

Newspaper Colour Profile Download - WAN-IFRA

colormanagement - Download

What I meant is one can convert from CMYK to RGB document colour modes. Then change the CMYK working space to “newsprint” and then change from RGB to (news) CMYK document colour mode. Make sure that this profile is assigned to the file, and change your CMYK colour settings back to your previous profile. You may then need to manually adjust some colours/tones to be closer to the original or to have a pure/cleaner colour build. Work on a duped file. The darkest areas of total ink will be limited by the CMYK news profile conversion.

[Amadís]

The colour mode and working space are different things?

[Stephen Marsh]

The colour mode and working space are different things?

Different but related... There are both RGB and CMYK working spaces with variable attributes based on different real or synthetic "devices"... They have a colour mode associated with them. Illustrator is not like Photoshop where we can directly convert to a new non-working space ICC profile with an associated colour mode on the fly without changing colour settings. In Illustrator we have to fudge it by first setting the working colour space for the colour mode we wish to convert to, then change the document colour mode, ensure that the correct ICC profile is assigned to the file (and remember that you will likely need to change the working space profile back again afterwards)

[Mike_Gondek]

For simple line art with  few shapes/colors, you can fix in Illustrator, so you can better contorl exactly your formulation of Rich black. First you need to find where issues exist, save a pdf copy as high quality print, and open pdf in acrobat. In acrobat go to ouput preview.

Then go back to Illustrator select one of your black fills then select  >> same fill color. Change the color, then hide. See if an other mixes of rich black exist and repeat process. When done show all.

Command 3 & option command 3 for hide and unhide are one of Illustrator oldest and most useful features for cleaning up files. You also should use swatches and global colors, but my post would get too long to explain, but wanted to make you aware of how can best work

[Amadís]

Tha you so ver much for the thorough explanation. The dark swatch is not black. I was thinking about reducing colour values to result in a global 30% subtraction. Would this be a good idea or would you rather reduce each colour by 30%?

[Mike_Gondek]

You can disregard 30% to fix this, you just need a 230% max ink weight, DMAX or maximum density. First please tell us exactly what your blacks are filled with?

So you need 230 DMAX, you could chaneg the black fill to 100 K for a 100DMAX, btu your black will look like a dark brown and show pinholing where the tiny paper fiber are not as abosrbant.

I would fill those somewhere between 100k 40c 40M 40Y for a neutral rich black of 220 DMAX  or 100k 20C 20M 20Y for160 DMAX. If you make the blacks look to glossy & rich they will pop too much and especially on logo look unbalanced. Wont look bad either way so don't overthink.You cannot do much about the ink priming the page to avoid pinholing in other colors, but if you don't go too dark on rich black they can increase ink pressure overall.

If you know what Anilox roller and line screen  please post. Don't worry if not, printing quality is so much better nowadays, my conmments might be overkill. But every pressman appreciates an easy job, and less environmental waste getting pressrun primed.

[Mike_Gondek]

Thanks for posting your art, as you can see our comments get so much better if we see the art. I encourage posters to do that with every post.

[meganchi]

If you save out a pdf of your art, then you can open it in Acrobat. Use the Print Preview tool in order to see total ink coverage.

[jdanek]

If I am not mistaken, Illustrator's color setting allows 20% dot gain, so you only need to knock down the color values 10%.