How to create 'matte', dusty looking materials

[ben_hamburg]

Now we need a comparison of the same materials with falloff map instead...
It´s still a bit hard to tell, I feel like the GGX approach looks better, because a falloff map distributes the "dust" too evenly, thus making it look a bit more "CG".
Adding in some grungy texture to controll the "dust" look, would certainly help even more with realism.

[DanielBrew]

I feel like the GGX approach looks better, because a falloff map distributes the "dust" too evenly, thus making it look a bit more "CG".

Yes that's certainly the feeling I'm getting. The 'dusty look' should be stronger where the light is stronger (I'll ignore the direction for now). My previous attempts at a realistic fabric material had a light/shadow falloff as well as a perpendicular/parallel falloff to control the strength of the effect.