Iray Materials? Where are they

Hi, all, I have decided to try Iray from Nvidia. So far I’m liking it. However, if there is anyone out there who is experienced with Iray, I cannot seem to find more than a dozen or so basic materials, no wood grain or concrete materials for architecture, no stone or fabrics. I have spent some time searching around, on Nvidia’s site, I have installed the MDL Material Ex. with the trial. Can anyone direct me to where I could find more materials for the library?

Thanks, Much appreciated.

Look for vMaterials where you got the iray demo.