@pbacot said:

Does the "shell" command work for this?

I am not familiar with the tool. Can you perhaps look at the one part and guide me if possible ?

Thank you for the replies.

I thought I was a bit unclear as what I want to do. Maybe my intended work flow will help to better understand.

Create 3D model in Sketchup Unwrap / Uv map model in Wings 3D. I know, I know, There are other better ones but I find Blender very intimidating. Export the UV. map as a image to be "painted" on. Import the Uv map image into sketchup and a apply to a square face. Trace the face lines (shells) of each part using SU's line tool. Apply the desired line style. Export the face with all the lines to a new image but this image must be the same size as the original UV map image.

To be honest I am not even sure what line style was used in SU to create the grime / dirt layer.

I will try your suggestions and post again if needed.

Thanks once again.