The invention relates to providing composite structures with a micro contoured surface layer. There is provided a method to adjust the roughness level of the micro contoured surface layer when manufacturing a composite and products thereof. The micro contoured surface layer may cover all of the surface or at least part of the surface area of the composite product. The roughness level of the micro contoured surface layer may be increased or decreased by controlling the process parameters. In particular, there is provided a method to increase the roughness level of composite material having a primary surface layer with a primary surface roughness by softening said primary surface layer of said composite material by heating and providing a secondary surface layer of said composite material surface with a secondary surface roughness by cooling said softened surface layer. Further, there are provided methods to determine and visualize the level of micro contoured surface layer roughness on a composite product surface.