I normally use 4 different workspaces for different things, and they are always the same. Can I make a different background image for each one of them? 

I would like an answer that works for GNOME 3 desktop environment, Unity and the Classic desktop environment. 

---

This question has multiple answers covering different Ubuntu versions:

* [17.10, 18.04 and later](https://askubuntu.com/a/1089402/1089402)
* [13.04, 13.10 and 14.04](https://askubuntu.com/a/334224/14356)
* [12.10](https://askubuntu.com/a/213514/14356)
* [12.04](https://askubuntu.com/a/159255/14356)
* [11.10](https://askubuntu.com/a/76049/14356)
* [11.04](https://askubuntu.com/a/76001/14356)
* [10.04](https://askubuntu.com/a/4500/14356)