Hi there. I don´t have much experience using textures and mapping in Rhino so this is my problem. I created physical based rhino material. The problem is, I can see those “seams” in texture even after I edited it in photoshop. So what I wanted to do was play with the texture mapping through UV editor. Everything seems fine until I apply it, then the texture turns black. The type of mapping turns to “custom object” and is black until I turn it back to type “surface”. But then the UV editing I did does not apply. Any suggestions ? Thanks. 
Can you attach a file which illustrates the problem? Without this it is hard for others to dig into the details.
Regards,
Terry.
Hey I actually think I found the problem 
. It was the ambient oclusion. I restarted the whole thing, started again from scratch and figured that mabye somehow I had the ambient set to low % on that specific mapping.