Phil, The data you are looking for is under the texturing/shading portion of the manual. Basically the layer tools become active when you change the type of shader from multi-channel (at the very top of the shader) to Layers List. You can then add multiple layers to the shader by clicking on the "PLUS" icon at the very bottom of the shader. Layers can also be nested, so you can have layers within layers. Pretty powerful. Depending on the type of layer, you have various options for blending them together. The type of layer I use most is Parametric Mapping because you have an opacity mask for blending. This mask has all of the features of any other channel and is quite useful. Otherwise the blending is set to additive (I guess) by default. The parametric mapping is also useful if you want to define separate areas on the object with their own shaders. .Painter