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enter image description here

Trying to figure out how to print this image of a motorcycle so that it doesn't have this halo effect (if thats what its called) when printed on top of 100% K. Tried a few different things but nothing seems to make much of a difference and it just clearly sits on top of the black without blending at all.

  • Are you printing on (glossy) black paper? In that case there might not be an ink that looks the same in your printer. Perhaps using gradually increasing transparency to decrease the density of ink dots might help a bit, but I didn't try that approach. – CodesInChaos Jun 20 '17 at 20:16
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    Cut the bike photo in two at the orange line. Set the lower part (with wheels) to overprint. – SZCZERZO KŁY Jun 21 '17 at 10:47
  • Could you point out where in the image that halo is? Like marking it in the image, or adding a zoomed in detail image? – Volker Siegel Jun 21 '17 at 12:23
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The black in the bike needs to match the background black.

If the background is 100% K, the bike needs to also be 100%k.

If the background is 40C0M0Y100K, then the bike needs to be 40C0M0Y100K

It may be easier to just add a transparency gradient to the bottom of the bike rather than adding a black gradient.

  • Probably it needs to be the other way arround. The black of the bike is the one that needs to define the black of the swatch. But yes, probably the gradient on the bike is the best option. – Rafael Jun 20 '17 at 17:38
  • I actually tried a gradient feather in InDesign on the bottom and it didn't seem to affect the printed appearance of the bike, which surprised me a little because I thought it would get rid of that grayish appearance at least a little. I'll try it again though. – Alex Monterville Jun 20 '17 at 17:39
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    I'd mask the bike in Photoshop, not InDesign. InDesign gradient feathers are okay.. but generally not as smooth in my experience. The gist of my answer is.. match the blacks :) – Scott Jun 20 '17 at 17:40
  • @Rafael that actually might work better – Alex Monterville Jun 20 '17 at 17:41
  • @Metis I definitely agree – actually tried masking in PS and InDesign but neither seemed to work in this case – Alex Monterville Jun 20 '17 at 17:43
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1. You need to edit your bike image in RGB. Adjust the levels so you have what is called a "black point" on the tires. This is one spot (or a zone) that is r0g0b0.

As you will probably darken the overall bike you probably need to duplicate the layer and use some gradient between the dark part and the light part. But that is another issue.

You can confirm this is black looking at the histogram or levels.

2. After this, you need to define the correct color profile in which your print should be. If it is a digital print you can use Fogra 39 for example, but for offset, you probably need another, like Swop2 or Fogra 27. Ask your provider.

3. When you convert the image to CMYK it will give you specific CMYK values of this dark RGB black to that specific conversion. For example, the values I know are c75m68y37k90 which are from using the Swop 2 profile.

4. These are the exact values you need to use in your black swatch. Not k100% alone or any empirical value like c50%k100%.


As the tires are grayish there is a chance your program is converting the r0g0b0 to only k100% This is only needed in a strange case where you have a black text.


P.S. (Do not use c100m100y100k100)

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This answer was originally to be a response to your comment, but it would have been too long and it does (I hope) help answer the question.

I actually tried a gradient feather in InDesign on the bottom and it didn't seem to affect the printed appearance of the bike, which surprised me a little because I thought it would get rid of that grayish appearance at least a little. I'll try it again though. – alxmntrvl 9 hours ago

I recall discovering many years ago working as a printer that with Adobe InDesign CS5, a color image or color layout element placed in conjunction with (overlapping) a black border or text or background design would alter the printing (CMYK) of the black to be CMYK instead of just K. Regardless of transparency effects.

In other words, the blending of a transparent CMYK element with a plain black line or piece of text produced a black that was printed (on the Xerox 700 Digital Color Press I was using) with four colors of toner. This made that part of the line or text look glossy, in contrast to the portion outside of the color blended area.

From your photo, it appears that the bottom part of the motorcycle is being printed as a process color (CMYK, probably 100% of all four) and the rest of the black background is just black ink (K). (This is the reverse of what Rafael's answer describes, but that's what it looks like to me. I worked as a printer as well as graphic designer, but I could be wrong.) :)

One possible solution is to make the entire black section (the background) CMYK black. I've used that solution, but I prefer the other solution:

The other is to force that part of the image to grayscale so InDesign won't print it with CMYK but just with K. The quick way I would use to do this would be to:

  1. Copy the motorcycle (in InDesign)
  2. Paste in place (so you have two copies one on top of the other)
  3. Resize the bounding box (crop) to the top edge of the black background. So in other words, you will have two half-motorcycle pictures, one being the part overlapping the black rectangle, the other being the top part.
  4. Change the color settings on the bottom part to grayscale.

When you print the resulting file the halo should be gone. (It's been a while and this was on an older version of InDesign, so please let me know how it goes.)

  • I added the note (on my answer) not to use c100m100y100k100) n_n – Rafael Jun 21 '17 at 7:11
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    Yes you were right that the box was 100% K and the black in the motorcycle was a mix of CMYK. I kind of just wasn't giving enough attention to that fact even though I was meaning to match the blacks/intending to do that, because I knew that was the problem. I also considered grayscaling the part of the bike overlapping the black by using the same method you describe, so its good to know at least I was thinking of solutions like other printers (I work as a junior designer/4-color digital pressman at a print shop). – Alex Monterville Jun 21 '17 at 13:11

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