The Noise functions are very useful to make the textures look less clean and artificial. They add for example aging effects, erosion, spots and scratches.

Here is a list of the Noise modificators:

	Erosion	Erosion simulating function to make your textures look aged.
	Pixel	Simple monochrome pixel noise.
	Randomize	Variate the shades of isolated areas.
	Scratch	Add directional scratches.
	Spots	Fractal, colored spots.
	Structure	Apply a multifractal pattern to the texture.
	Tears	Fractal, bright and dark tears.
	Variate	Variate the shades with a coherent noise.