This effect was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
This filter generates grunge. It allows you to add as much or as little grunge as you like, plus it has a grunge overlay for grungy grunge. Scan lines can be added to the grungy grunge making it even grungier. The grunge can be used on its own or the filter will abstract the edges of an image and grunge them up. The grunge comes in red, green, blue or black. The grunge and the grungy overlay can be scaled and varied independently. There are twelve base grunges with twelve grungy overlays. There are three modes; image, edges and paper - each can be used in any combination. The ink can be faded for the appearance of aging. There is a mode for border or vignette which can be tapered or faded to zero.
grunge grundge dirt mottling
This filter has earned its author one of our rewards. They are given to the authors of popular filters and include a free copy of Filter Forge.