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Confusion with which black mix to use for what

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samjoy

Programmer
Apr 28, 2009
103
GB
Hi When specifying a black background for a flyer which will be both on web and as printed flyer I am getting really confused. My flyer background is C0M0 Y0K100 in indesign ( indesign standard swatch, in preferences display of black overprint unticked. In the flyer placed is a photoshop image with black background filled with black,edit-fill-black, double click this black swatch thumb and it confirms C0M0Y0K100 in PS. When i export to PDF my flyer background looks grey compared to the black image BG from the placed PSD image. Why is this? I went on a google search about which black to use but am still confused about all the blacks, I have the following to choose from..

RGB Black | R/0 G/0 B/0...this is for the web flyer
PhotoShop® Black | C86 M85 Y79 K100
Neutral Rich Black (also known as Rich Black) | C40 M30 Y30 K100
Flat Black | C0 M0 Y0 K100
Designer Black | C70 M50 Y30 K100
help ! which black generally for my print design work and is it a case of inputting the numbers to specify it in PS,Illustrator,Indesign and all will display the same black? Many thanks. Sam
 
Hi

Pantone Process Black should look black when you make the PDF file from either program.

In Photoshop click on the color selection icon to open the color Picker for the foreground color.

Click in the bottom left corner of the panel.
Click on the Color Libraries button.

You should see Pantone Process Black in the bottom left corner.

Use that in both programs.

Mike
 
...the use of black ink is dependant on a number of factors...

...if you have large areas of solid black on a design it is advised to use an underpin using the other process ink colors C,M,Y...

...varying these additional CMY inks into black ink will give you either a warm, neutral or cool black depending on the % used...

...never use 100% of all four process colors in any work you do, this is known as 400% ink coverge (100% on each color ink channel)...

...and if for newspaper print, you again have to be careful about how much ink is used in a mixed ink black, typically no more than 220% to 240%, this includes inside bitmap shadow areas...

...obviously if you printing a black ink only job, you need to ensure your using around 100% black for large areas of coverage. Black ink tints will vary in shade depending on what paper stock is used, it differs between coated or uncoated papers...

...it is best advised you don't turn off the overprint default black in indesign:


...instead, create your own black swatch, this will then knockout by default, for anything you want to overprint with black use the indesign default black instead, switch between the two essentially...

...using edit > fill > black in photoshop will produce 100% black assuming you are in greyscale mode, if your image is in RGB or CMYK you need to recheck your image...

...the display of black in indesign and illustrator is determined in the preferences as per attached screen image link provided above, imported black will look different to indesign black depending on what your preferences are set to...

>>> is it a case of inputting the numbers to specify it in PS,Illustrator,Indesign and all will display the same black? <<<

...if you want the same black ink mixes then yes, you do have to specify them in each program and assign them correctly...

...however, as mentioned above, if your dealing with greyscale images, your indesign preferences will determine how the indesign black displays compared to that of the imported greyscale images. With "display all blacks accurately" enabled in indesign or illustrator, the imported greyscale 100% blacks will look different, even though they are in fact the same...

...personally i would use the Neutral Rich Black (also known as Rich Black) | C40 M30 Y30 K100, this is more than sufficient for most rich black scenarios when dealing with CMYK artwork...

...also for your web RGB needs, just export your artwork from indesign to PDF and convert all colors to RGB in the output options of PDF export, use 72dpi compression on images etc. I wouldn't bother creating a whole new file just for the web and manually changing all the colors, just let the PDF export deal with it...

...that is what it is there for to do color conversions in the PDF export stream and save people from a ton of work...



andrew

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...you will also be best advised to use the indesign separations palette (window > output > separations preview), and check your plates there by turning it on and then turn the black plate off, you will then be able to determine any problem areas on your artwork...



andrew

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...and don't forget be extremely aware of the photoshop swatches palette in CMYK mode, as well as using the edit > fill > black option in CMYK mode...

...if you want 100% black ink in CMYK images, then specify this value manually in the color picker dialog...


...this probably where you have fallen foul if your PDF is displaying different densities of black...

andrew

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...it is also advisable to keep the indesign (and illustrator) preference to display black accurately:


...that way you can see on screen in indesign the difference when importing CMYK black images compared to your own indesign black swatches...

...also use the separations preview palette...

...and don't forget that greyscale images display different even though they use the same % of black in indesign and photoshop when using the "accurate" display of black preference...

...again, use the separations preview palette to verify all your work...

andrew

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wow thanks guys, really comprehensive black tutorial here! cheers
 
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