Hello SE, It looks like the difference between your shader and mine is the ability to chose which face is mapped to. Your's has the shape layer as a subset of the "Whole Object" instead of a different face like "Front Face 1". I suspect that it is simply the order in which the shader is built. 1. Creat the glass shader as a Multi Channel like you've done, 2. Using the mapping tool, draw the rectangle where it needs to be. This should automatically convert the shader to a Layers List shader with the newly drawn rectangle on the appropriate face. Since I can't see the extended shader tree in your sample, the solution may be as simple as dragging the rectangle layer to the appropriate face within your current shader. Always a million ways to do the same thing eh?... Mark