How to center cover graphics?

Centred means to have the centre of a feature printed on a cover (i.e. photograph, graphic element, text) aligned with the axis that runs vertically through the centre of the cover. Where there is a shift by even a few millimetres in relation to this axis, there will also be weeping and wailing and gnashing of teeth. And all the more so when metallic foil is applied to the cover as an enhancement (either through hot stamping or using the 3D Touch technology). Even the most beautiful book cover will look messy then and as if created in a hurry. Do we really want our book to evoke this type of feelings even before we get acquainted with its content?

So far, it is all straightforward. It gets complicated, though, when it turns out that we are not always to align things with the centre.

As far as geometry is concerned, it would be difficult to argue about where the centre is. Mathematics are hard to cheat. Planimetry is inflexible and the centre of the cover simply lies exactly in the middle of the distance between the spine joint and the edge of the cover. On the other hand, we have to remember that we are not talking about precise geometric determination of the centre of the cover. This is where we need to take optics into account. It is extremely easy for the human eye to be deceived. Who cares that the features on our cover are centred perfectly when readers get the impression that something is not quite right there with the printed elements looking as if shifted one way? Sometimes, in order for the graphics to seem positioned right in the centre, we have to resort to a ruse.

Depending on what type of cover we are dealing with, the axis with which we want to align what we print on it will be positioned slightly differently. To make everything clearer, we will use the drawing from our cover generator.

It is easy with softcovers (either sewn or perfect bound). We centre “geometrically”, i.e. in relation to the vertical axis that runs through the centre of the front cover. Naturally, the crease will also count as part of the front cover. In other words, our vertical axis lies between the spine joint and the edge of the cover. We obviously do not include bleeds as we only want to centre the visible part of our cover.

It is a great deal more complicated with hardcovers (either sewn or perfect bound). And the hinge is to blame here. Where our creases are subtle and hardly visible at first glance, our hinges create a very evident division that has to be taken into account. Have a look at the drawing for it to become clearer.

To determine where the centring axis is to run, we have to identify two areas within the cover: our hinge and the part of the cover that we are left with once we take the hinge away. They are marked on the drawing with dark and light blue colours, respectively. Let’s consider the width of the hinge and split it in half. And now let’s add half of the width of the hinge to the rest of the cover. The centring axis will run halfway through the width of the resultant area.

We have to be particularly careful with centring when dealing with frames as they count amongst the more challenging elements that can be printed on a book cover. Every single millimetre makes a vast difference here.

The geometric shape of the frame will plainly expose any inaccuracies in the design. If the frame is not perfectly centred, for instance it is placed at a greater distance from the top edge than from the bottom one, it will become painfully obvious in an instant. Even a reader with only the slightest sense of aesthetics will feel his eyes hurt when looking at a cover designed that way. Which is why we have to approach the issue of frame placing with particular reverence.

The abovementioned rules stem from our experience in book binding and printing. But there is one more thing that becomes obvious after many years of working in the industry: there are instances when the rules simply fail to work. The creativity of cover designers is unrestrained. There are certain graphic solutions where strict adherence to rules would lead us astray. What if, with a softcover publication, our designer decides to apply a distinctive colour on the spine all the way to the crease? This colour split will change the proportions of the cover, so if we follow our rules, we may get the impression that the centred graphics come too closely to the spine. If something looks better when centre aligned with other points of reference, it is definitely worth trusting our intuition. Usually, however, there is no need to reinvent the wheel as ready-made solutions are within arm’s reach.