Thanks. I was thinking to use a map, bu if viewed up close is there a way for the perforations to appear transparent? Sorry, I'm a bit of an amateur on Vis. The steel grate walkway is causing me most problems (see link for an idea of the type of material I'm after). It's quite important that gaps are apparent in the texture and that the depth of the grate is visible... Can this be achieved with a map?
http://www.usffab.com/usffab/images/USF6685.jpg
Thanks