You can add 2 types of image to a header background:
1. Website wide
This is as wide as the monitor screen. The ideal dimensions for this image are: 2gkatsanos [11:55 Agkatsanos [11: 56000 pixels wide at 127 pixels high.
An example: taaltelefon.be
2. Page wide
In this case, the image is as wide as the margins of the website. Here are the ideal dimensions: 1140 pixels wide and 127 pixels high.
Should the image be larger, it will be automatically reset.