Wednesday, January 26, 2011

Rich black - the problem of black in presswork

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  1. Hey Gordo a great post :) Just some additional things perhaps?

    In some DTP systems, like Adobe InDesign, there are options in the preferences for how the Black is DISPLAYED. You can choose to display all as "Rich Black" or "Display All Blacks Accuartely", when you choose the former you get the following onscreen representation:
    http://img718.imageshack.us/img718/1329/blacksr.jpg

    If you have an image with black in the background and you're overlaying Black on top of this in your layout, it's important to match the black from the photograph for the colour build in the black box (frame) you're creating in the layout, otherwise there will be mix of blacks where they overlay.

    In the below image I used the same builds as before - but I added one more, where I took the values from the Image and used that for the build of black.

    http://img213.imageshack.us/img213/350/importantmatchingofblac.jpg


    It's also important not to go over the ink limit when building blacks. If you go over the ink limit it may cause the ink not to dry, causing set-off (where ink is transferred to other sheets when on top of each other). Check with your printers regarding ink limit. (that is where you build the black of C85, Y50, M100, K100 would = 335 where the sheet may only hold 300!)

    DO NOT USE REGISTRATION for your black solids. This is a colour solely intended for REGISTRATION marks, it uses 100% of each colour (including spot colours) to make the build).

    And finally if you're reversing type out of a black,
    do not use a thin font,
    or a font with thin serifs,
    don't go below 10pt (roughly),

    DO
    do use a wider kerning
    do use a slightly bolder font (if you have a semi or demi version that is perfect, use bold if you have to)
    do use a SANS SERIF FONT if possible (it's not essential)

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  2. Thanks Eugene! Now I don't need to do a "Part Two" on the topic! ;-)

    best, gordo

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  3. What do you think about rich formulated black (Onyx black)?
    We've had some good success with it and it saved us some money as well as we avoided registration issues.

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  4. Oh do please keep them coming :) I'm sure your post will be a lot more informative than mine :)

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  5. @Zoran - The only black ink named "Onyx" that I know of is manufactured by Collins Ink for inkjet printers, not offset.

    Which ink supplier are you using?

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  6. Sorry Gordon, it's not Onyx but I found that it's easier to explain as people know about Onyx black mostly.
    The "rich" black we are using is called "Intense Black", it's from Sun Ink Express series, 24

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  7. @Zoran - Interesting because I can't find any info on the Sun Chemical website for "Intense Black", "Rich Black", "Express series 24", or ""Express" There's also no info in my collection of marketing literature from the company. So I can't get any info to see what this ink is about - so I really can't comment.

    If you've have any literature yourself, maybe you could scan it and email it to me? pritchardgordon @ gmail (dot) com

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  8. This is a hot topic amongst designers, so thank you for posting!

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  9. Four questions:

    1. Does your recommended CMYK formula for Super Black (as above, 50C/40M/40Y/100K, DMAX: 230) assume the process is sheet-fed offset?

    2. Would it change if running on a web-fed press (assuming a similar paper)?

    3. Would it change if running UV inks (assuming sheet-fed offset and a similar paper)? AKA, would you push your DMAX due to the in-line curing? If so, how?

    4. Lastly, if prepping advertising artwork which features a large flood of black (that bleeds all sides), to be run in numerous and various large-run news and fashion magazines, what would you consider to be a safe (and predictable) Super-Black formula?

    Thank you!

    A.

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  10. 1. Yes - sheetfed.

    2. No - web offset can handle 230% max ink coverage.

    3. You can increase solid ink density or (TIC) Total Ink Coverage more easily with UV/Hybrid inks because of the in-line curing. But...there's a diminishing value to doing that. Once you've hit a level of "blackness" on a press, adding more ink will not make it any blacker. I.e. once the ink blocks all the light reflecting off of the substrate adding any more ink won't make the black any blacker. That point is usually reached at about 325% ink coverage.

    4. I would check with a media representative for the magazines to confirm since a large flood of black is unusual. I would use 50C/40M/40Y/100K or slightly higher. You should be safe with a maximum of 75C/62M/62Y/100K, for a TIC of 299% (1% less than SWOP's maximum).

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