Overprint? What’s that?

What is Overprint?

Overprint is a function that you can activate or deactivate in your design software, which basically entails that one colour gets printed over another colour in your artwork. When used intentionally, overprint represents an additional way to create artwork that is visually interesting and distinctive. However, if overprint is turned on without your realising it, you will probably end up with prints that look significantly different from what you expected when designing them.

Artwork with and without overprint

Basically, if overprint is turned off for your artwork, the colour underneath will be “knocked out” so that there is no colour mixing, and only the colour on top will actually be printed. In other words, with overprint turned off, only the top colour is printed on the paper when multiple colours are superposed in the artwork. On the contrary, when overprint is turned on, the colour underneath gets printed as well and the colour on top simply printed over it as a second layer.

With the bottom color knocked out, this artwork:

An artwork with two layers of colors in it

Can be seen like this:

What Knocking out basically looks like for that same artwork

When bottom colours are knocked out, colour mixing is not possible and therefore the only colour printed on the paper is the top one. With overprint turned on, the superposed colours mix, and create a colour that is different from the top one.

Sometimes the knock out behind dark colours can be seen if printing equipment is not set up perfectly, in which cases it’s better to turn overprint on. Turning on overprint is usually done to create visually special effects and to print black over lighter colours.

To manage the Overprint setting in Adobe Illustrator, open your artwork and go to Window > Attributes to select the options. Overprint can also be simulated in Adobe Acrobat by selecting Output Preview.

Setting up artwork files for printing can be tricky, and unexpected outcomes occur frequently. At Zenprint we want to help you to avoid this, and therefore try to cover most of the problem areas in blog articles. Keep posted and check our blog on a regular basis for help and tips about online printing, artwork design and closing, and print marketing in general.