Many of the designers like to use dirty texture as the background of website or painting.I also like them(so my homepage is a dirty old bag with old cards^_^).The dirty effect could be designed in either hand painting or photo shooting.You can also make it in the photoshop(the "cloud" filter+"noise" filter could make good effect of this).When I was at home in this winter vacation I had shoot many texture of different things.Here I put some of these textures for those who love dirty(some were downloaded from the internet).~~.