Now we'll explore some other use and dirty a bit some wall texture! Same process of the previous example here is a render of the base texture, rather clean!

We add the same brownish layer used for the metal plate and we have the result in figure G, the variations looks too much blurred for your tastes? just change the procedural type from "FBM noise" to "Puffy clouds".

Fig. G

We get an output like figure H. And here we discover a first difference between the two: puffy clouds gives a "sharp" result by putting the color in a more precise and isolated way, while FBM noise is rather smooth and blur (although playing with settings can lead to very different results). puffy clouds this time fits more the background texture imo, so we'll use it.

Fig H.