I seem to remember a while back someone was asking about diery skin textures in poser and I wondered the same myself. So I took Cathrina's Kain texture into photoshop, created a new layer, and used the clouds filter, with the background colour set to a mid grey and the foreground to a dark brown. I then set the layer to "hard light" and turned the transparancy down to about %60 and added some noise and a gaussian blur. When I took the texture into poser I found that I hadn't got it dark enough so used the paint bucket to tint the model's head a with a light grey. I was quite pleased with the result and wanted to share it here:)

This is without the skin being tinted.

The non-tint version actually reads better as "grimy" than the first. The first is just too evenly dark to read as dirt.

Yes. A very good job.

I agree the non tint is better, but baby make the skin just a little darker with the Poser "Surface Materials" > "Object Color".