Old iron manhole I found while I was on holidays in Oxford. I found the pattern quite interesting, so I thought I'd give it a go. Although it has proved itself a bit more challenging than expected, I managed to finish the material in roughly a work day, so I'm quite happy with the result. This material has 2 parameters: an Age slider which controls various effects such as dirt, erosion and scratches on the surface, and a specific slider for scratches, which can be added indipendently to the "young" surface