When creating graphics, you often have to arrange elements such that they overlay. There are two ways of masking the hidden elements.

One possibility is the deletion of the hidden parts of the elements. If you do so, however, you will not be able to use these elements as a whole again. If you want to avoid a deletion, you can apply the coverage technique. This is especially helpful in conceptual phases where a customer might demand frequent changes and editing in an illustration. In this technique, the elements that are covering others are filled with color, mostly white.

In the illustration above you can see a cube that is overlaid by a second cube. The grey lines represent the covered area. Instead of deleting the covered lines, you can cover them with an element filled with background color. For easier recognition, we have colored the element in the right illustration grey. Now, if you have to arrange the smaller cube differently, the covered areas will become visible again.