In the same way that a frame around a picture makes it complete, so a suitable background at the rear and possibly sides of a model railway layout, will help to define the layout and make it complete. Its presence serves as confirmation as to what is part of the layout - and what belongs outside it. Most backgrounds that I am aware of, are photographic prints of very good quality. Usually, they come in a set of two, or sometimes three sheets, that form a continuous scene generally about 2700 mm long by 500 mm high. For those who require a longer background, there are two pairs of backgrounds where the sections are able to be extended either way for as far as is required and one that has end points that match each other, so that it too, can be extended as far as required.

The largest group of model backgrounds is from Faller.

The two pairs are:  FA180511 & FA180514 (each of which is made up of 4 pieces stretching 3880 mm x 650 mm high) . and FA180516 & FA180517, (each of which is made up of 3 pieces stretching 2900 mm X 450 mm. high). The final background that is able to be extended indefinitely is FA180513. (a 2 piece background stretching 3200 mm X 970 mm

For smaller layouts, there are: FA180504, FA180505, FA180509, FA180510, FA180512, FA180515, FA180518, FA180800. 

Viessmann produce a small range of model backgrounds under the Vollmer brand. Two of them, VO46105 & VO46112 are of a blue sky with clouds and notable for being different sized versions of the same photograph, to suit different situations; while the third is VO46106, an alpine scene.