A composite has a fibrous layer bonded to an outer side of an impermeable barrier layer. The composite is assembled on a panel composition that provides a panel substrate. The barrier layer isolates the fibrous layer from the panel composition. The fibrous layer is exposed from the barrier layer and is free of the panel composition to adhere another material to the panel. Alternatively, the composite has another fibrous layer bonded to an inner side of the barrier layer for embedding in the panel composition.