hello bloodsong, Yes, I think you're right, except for the last one: When I scale my Poser humans, the feet don't stay on the ground. They scale (and rotate) around the abdomen, unless I set the origin to 0 0 0. As far as I can see, Poser's scale channels perform a common scaling operation, that is, every vertex moves on a straight line towards the rotation center (down scaling) or away from the rotation center (up scaling). Here's a little experiment to prove the theory: 1. When you down scale the geometry, all vertices move towards the center point. When you down scale more and more, the vertices should pass the center point, and then move away in the opposite direction. You can for example move the 'xScale' channel towards 0, to move the vertices on a straight line along the x axis towards the x coordinate of the center point. If you set a negative 'xScale', the vertices should move beyond the x coordinate of the center point, so that the geometry is mirrored in the yz mirror plane. Right? 2. Of course, this doesn't work, because you can't set negative scale channel values. 3. But if you use a valueParm master channel, and make the scale channel a slave, then it works. You can set the master channel to negative values, and the scale channel slave follows. 4. The negative scales work as expected: Is you set a scale channel to -1, the resulting shape is the mirrored variant of the generic geometry. Negative 'xScale' mirrors in the yz plane, negative 'yScale' in the xz plane. Negative 'scale' mirrors the geometry in the center point (which is the same as mirroring in the xy, the xz, and the yz planes). 5. The resulting geometry has 'reversed normals' (as expected): The scale channels move the vertices, but don't adjust the facets. Therefore, the surface of the mirrored geometry is 'inside out'. You can use the 'Reverse Group Normals' command in the Group Editor, to adjust the normals.