Ben wrote:
I am having trouble with colours printing in an incorrect way. If I draw a yellow box, for example, and then place a black box over it the yellow behind the black box seeps through when I print. How do I stop this?
Yes, you have to be careful with that! I remember seeing a full page ad in a glossy magazine of a shirtless runner, with a giant black stripe over his, um, privates. The whole point of the advert was that he was supposed to be naked (you know, with a message something like “don’t get caught without protection”). But the designer had used solid 100% black ink. The result was that you could see right through the black stripe and see that he really was wearing running shorts. The whole point of the (obviously expensive-to-run) ad was ruined due to 100% black ink.
The problem is that black ink isn’t truly solid black — it’s more like charcoal gray. And worse, the [Black] color in the Swatches panel will, by default, always overprint anything under it. You can get a sense for that if you turn on View > Overprint Preview and open the Preferences dialog box, click the Appearance of Black pane, and set the On Screen pop-up menu to Display All Blacks Accurately.
Normal black on the left, rich black on right
There are several options for making your black box look more solid and stop the yellow from bleeding through:
- You could turn off the Overprint [Black] Swatch at 100% checkbox in that same preference pane. I do not recommend this, because you probably want some black stuff (like normal black text) to overprint.
- You could set the black frame to a tint of 99%. That would force the black to knock out instead of overprint the yellow frame. But I don’t recommend that either.
- You could make a new color swatch of 100% black and apply that instead. You can even call it Black. That will knock out, even if it’s 100% black, because it’s not the built-in [Black] (with brackets) color.
- But the best thing to do, if you are printing in color, is to create a “rich black” — a CMYK color swatch which is a combination of colors, such as 30% cyan, 20% magenta, 20% yellow, and 100% black. (Different people have different recipes for a good rich black.) This will give you a true “black” color on the page, full of vigor and vim, ready to overpower anything you put under it.
So… moral of the story: Don’t get caught exposed and without protection! Use Rich Black!
This article was last modified on December 20, 2021
This article was first published on November 27, 2009
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