The order in which paint layers appear on a model can be rearranged by dragging them within the list in the Layers window. This changes the stacking order of paint layers so that a layer appears above or below other layers. In the resulting texture image, the paint appears in front of or behind other paint.
Paint layers can also be dragged to other paint channel types (diffuse, specular, gloss, bump) thereby changing their effect based on the layer channel type. For example, duplicating and dragging a diffuse paint layer into an existing bump channel would result in changing that layer’s characteristics to a bump texture that is fully aligned with the original paint layer. The amount of bumpiness is dependent on grayscale values in the image and the Bump Depth setting in the material properties.
Painting and previewing a specular map can be difficult as the specular effect is somewhat transparent as you paint it depending on the scene lighting. Dragging the specular layer between the Specular and Diffuse channels (temporarily) lets you more easily preview and edit a specular map.
You can drag a paint layer to a different paint channel type (diffuse, specular, gloss, bump), if it exists, so that the paint represents the characteristics of that layer type.
