Turf comprising artificial or natural turf fibers and fiber optic filaments extending between the turf fibers. The present invention also provides a method of marking a surface comprising the steps of providing a light source, providing a surface to be marked, providing an optical material capable of illumination by the light source, configuring and arranging the optical material, the surface, and the light source such that illumination of the optical material is visible on the surface, and illuminating the optical material. The present invention also provides a method of manufacturing turf comprising the steps of providing a turf surface, providing optical material capable of illumination by a light source, and threading the turf surface with the optical material whereby illumination of the optical material is visible on the surface. The present invention also provides a method of manufacturing a surface comprising the steps of providing an optical material, providing a surface, arranging the optical material such that it extends above the surface, and trimming the optical material such that it is flush with the surface.