adobe photoshop - how would you recreate the distorted/noise effect that google uses in their new material design illustrations?

I've been trying with brushes but it just doesn't get close to this. Has anybody been able to accomplish this effect? how did you do it?

I'm using photoshop cs6

Answer

Follow this! https://medium.com/google-design/salt-pepper-the-art-of-illustrating-texture-c962dc67cc35#.aa24epyn7. Finally a good method, and that by a googler!