Managing Colours
A printer uses a mix of color inks to produce a high-quality black printout. A rather straightforward process can be tricky so we prepared this article to assist you with this
Last updated
A printer uses a mix of color inks to produce a high-quality black printout. A rather straightforward process can be tricky so we prepared this article to assist you with this
Last updated
Black (0,0,0,100) is not black; it is a dark grey. The reason it is grey, rather than black, is that the ink is partially absorbed by the paper and is in any case a very thin coating, so some of the white shows through.
When using saturated black, it gets darker than when using 100% ink. For best results, we recommend a high black value for all printed products: C60, M40, Y40, K100.
C0, M0, Y0, K100 usually result in very dark gray colors but not rich in black. We usually see black by default in Adobe Photoshop, which is used instead of the recommended black color.
The problem with using C75, M68, Y67, K90 is that it will not print very rich black. This setting is the result of the conversion from real black to RGB to CMYK. The print result is usually dirty due to the over-saturated color structure.
In InDesign and Illustrator there is a preference setting called "Appearance of Black" which can be set to display blacks "as black" or "accurately." For print work, you should always set these to display and print blacks accurately so you don't make an embarrassing error.
Additionally, complete the following steps:
Image > Mode > CMYK Colour is checked
View > Proof Setup > Working CMYK is checked
View > Proof Colours is checked
The main thing to remember with rich blacks is that your mix should always add up to less than 300% coverage. Too much ink results in "bronzing" - a bronze sheen created by a layer of ink that can't be absorbed by the substrate, so it just sits on top. It's also almost impossible to dry completely, so you'll add time to the job.
This is why you must never use the [Registration] swatch in a layout. [Registration] is 100% everything: CMYK plus any spot color plates. Registration marks are the only place [Registration] swatch is used, but they are in the slug, not in your artwork. Your layout program does this for you automatically when you export to PDF and select the option to include registration marks.
Here's an instance where this subject can get very important: if you have a photograph with a black background and you place it on a 0/0/0/100 background, thinking they will merge invisibly, you are actually placing RGB black (which is a rich black when converted to CMYK - check it out in Photoshop) on top of dark grey. On your screen it might look okay, but in a newspaper or magazine ad it will look pretty bad.
In case the submission was due yesterday and there is absolutely no time to fix the file then printing a screenshot is the quickest solution. Although it will compromise the quality of the print, the job can still be presented with the intended colours. Note is a very last resort to refer to.
