diamond plate diamond sheet grid metal pattern sheet metal texture abstract antislip background bright bump-map diamond-patterned diamond-plate diamond-sheet diamondplate industrial industry light patterned patterns paving reflection reflections reflective sheet-metal shiny silvery surface surfaced surfaces textured textures walkway construction diamonds metallic non-skid oxidation oxide paint painted rust rusted rusting rusty urban weathered worn age aged grit grunge Portland sidewalk surace