Hi Andrew, Those are good user interface ideas. Along the lines of your suggestions, I think providing an initial colormap that has more nodes (maybe 3, 4, or 5), and multi-colored (maybe rainbow), would better show off the volume rendering capability. The currrent white cotton ball you see by default in solid rendering mode is not very useful. That said, I have yet to see a compelling advantage for the solid rendering in molecular structure applications over surface rendering. It is true that 3D medical image scans often are shown with volume rendering, but that data has different characteristics. Since I have no examples where the solid rendering has proved very effective, enhancing it has low priority. Still I will keep your color map user interface suggestions in mind with the new surface colormapping tool (not yet released) that uses the same histogram interface. And we also use that histogram interface with the "Render attributes" tool. Thanks for the suggestions, Tom