Yesm in fact it could be a matter of sikmply dragging a 'shellac' slider would allowed you to control the blend of two procedurals in terms of depth.. ie: how deep into the object the first material lasts before the 2nd material appears. Slider all the way to left means shellac is off and first material is the only one visible, slider in the middle means that the first material is one quarter of the width of the object in, and slider all the way to the right means that you can only see the 2nd material. Scott