Baz, I have a little bit more info about what is happening here, since I read Angel's first post on this over in the 3D apps forum. It seems a boolean difference has been used to make the figure have a wall thickness for rendering a transparent effect. The problem is that the object used in the subtraction was a slightly scaled down version of the figure, which intersected the larger figure in several places, and has removed parts of the larger mesh. The way to do this is use an app that can do parallel offset, shelling, or thickening. It's all the same function, but some apps refer to it differently. Chris