Mark, I have certain hesitations in saying this, but I don't think that what you're asking is possible in Vue. Let me get this straight: You want to , in essence, be able to assign a mask to a certain region within a previously-mapped object? I don't really understand, but if I read you right, you woukld have two choices. Within Vue itself, I believe it would be possible, though probably very dificult. You might play around with the "Origin" setings in the material editor... But it sounds more like you want to UV map specific regions, like UV Mapper would do, but within the program itself. That's a tough call. I know that Vue has a different mapping scheme for it's own primitives than it does for polygon meshes..... I would recommend UV Mapper for what you want, and even better, UV mapper Pro, once it's released. In essence, Vue doesn't have many limitations to how it deals with materials, but it cannot set up new material groups on it's own.