Joaca-te cu noise putin. Dar probabil este un brush.

Adding noise to brush strokes (Photoshop)

  1. The Noise option adds additional randomness to individual brush tips. This option is most effective when applied to soft brush tips (brush tips that contain gray values).
To enable or disable noise in brush strokes:
  1. In the Brushes palette, select Noise on the left side of the palette. A check mark indicates that the option is enabled.