Images acquired from the same area in a newsprint sample.

The surface texture of paper is composed of stochastic and periodic features such as dirt specks and wiremarks, respectively.

• Left image) Dirt specks (dark particles) are introduced with recycled deinked pulp (DIP).
• Middle image) in optical formation dark and light regions may correspond to areas of high and low content of paper components.
• Right image) The wiremarks are caused by the wire in the forming section of a paper machine.