Whoever coined the expression “as simple as black and white” obviously never worked with four-process print. In this world of tiny dots, separations and registrations, trying to achieve a true, rich black can be more difficult than you might expect. On the other hand, maybe not. Maybe you’ve experienced the string of a disappointing black.
In this article we are going to consider the nature of black in the context of CMYK and how to create striking blacks that look as rich on the page as they do on the screen. If you don’t understand the underlying premise behind CMYK, we suggest that you read the article Getting to Know RGB and CMYK, which explains the differences between these two common colour models.
To begin, let’s consider the very nature of black in CMYK. Basically, there are two general forms of black – plain black and rich black. Each has its own strengths and weaknesses, and by learning about these areas, you can learn how to make the best use out of both types of black.
Plain Black
Basic black is, essentially, just what it sounds like. In CMYK terms, it uses 100% black (100K), but 0% of each of cyan (0C), magenta (0M) and yellow (0Y). Now, to a design novice, this must seem entirely rational. You want black, so using basic black only makes sense, doesn’t it?
Not necessarily. The truth of the matter is that not all blacks are created equal, and plain black is just that: plain. And, when it is laid down on paper, it actually comes back looking less like a real black and more like a very dark grey. Even some graphics programs, like Photoshop or Illustrator, will render plain black as more of a very dark grey. The following block of colour was created using plain black in Photoshop.
Notice how light the colour is, at least for a colour that is supposed to be black. Fortunately, in programs that do display plain black in this way, we can make adjustments to change plain black to rich black (we’ll learn more about this below). On the other hand, some programs, like InDesign, have colours swatches that are simply called “black.” Unfortunately, while this black is essentially a plain black, it does appear darker than plain black in Photoshop or Illustrator. In fact, it actually appears dark enough that an unwitting novice could easily assume that it was actually a rich black, only to be hit with a nasty surprise when the final piece comes back with blocks of dull, plain black printed across the piece. It’s not a situation you want to be in, so let’s turn to the bolder alternative – rich black.
Rich Black
The simple solution to avoiding the dullness of plain black is to give it a little something extra. Instead of using a colour of 0C 0M 0Y 100K, try adding a bit more colour into the black. For instance, you might create a rich black consisting of 50C 50M 50Y 100K. By adding this extra colour into the black, you allow the ink to absorb more light, and thereby creating a darker shade of black.
In this case using an even 50% for cyan, magenta and yellow will create a predominantly neutral black. However, there may be instances in which you want to give your black a slight tint. For instance, if you were working with a piece that was predominantly blue, you could increase the amount of cyan and decrease the amount of magenta and yellow. Something like 60C 20M 20Y 100K might work well.
If you are working from a photograph, consider selecting a black out of the image and using that as your rich black. This is especially effective if you were wanting to expand the borders of an image like this:
In this case, we would have to convert to image from its original RBG to CMYK. In Photoshop CS2, the black around the edges of the image is converted to a value of C75 M68 Y67 K90 (which is a fairly standard conversion from R0 G0 B0). If we were to expand the edges of this image, we would use the same value of rich black that already exists within the image. That way, when the image is printed, the original black and the new black will blend together seamlessly.
Too Much Colour
There is such thing as having too much of a good thing, and working with rich black is no exception. You may wonder why I suggested using a formula of 50C 50M 50Y 100K rather than 100C 100M 100Y 100K. The reason has to do with the sheer amount of ink that would be put down on the page, which may not dry before the page comes into contact with other paper. Obviously, this would result in smudging that would very likely ruin both pages.
For this same reason, avoid using registration swatches, which are used to print registration marks. Because these registration marks need to appear on every print pass, the registration swatch is automatically set to 100C 100M 100Y 100K, and as we have already established, this will cause far too much ink to be laid down on the page.
So, the rule of thumb with black is to either use the default, plain black swatch that is often provided by default in programs like InDesign, or to create your own rich black swatches. If you elect to use rich black, another good rule of thumb is to make sure that your total CMYK percentages do not add up to more than 300% (though with some types of paper, this percentage might be marginally lower).
When Plain is Enough
When working with graphics, you will usually want to use some variation or rich black for large areas of black or when expanding or otherwise altering an image with a lot of black in it. However, there are other situations in which plain black is more than adequate.
One such instance is in the use of text. Unless you are using an extremely large, thick-stroked typeface in close proximity to a rich black graphic, plain black is the way to go. The contrast against the white paper that surrounds it will make your type appear very dark, and by using only one colour, you will avoid any issues of fuzzy type that might arise from slight registration errors.
Conclusion
Now that we’ve worked through the differences between plain black and rich black, don’t let what we’ve discussed keep you from using black in your pieces and designs. Working with black is not really all that difficult, and once you grasp the differences between plain black and rich black, you will be able to start applying those concepts to your own designs and start getting the most out of black. Soon, you’ll be able to create stunning and eye catching pieces that make use of the elegant beauty of black!