background cover iron metal non-skid oxide plate ridges rust San Francisco sidewalk surface texture urban abstract aluminium aluminum backdrop blue color coloration colors colour colours decorative distinctive ductile-metal impressions interconnected interlinked light metallic raised shaped shapes sheet shiny stippled style surfaced surfaces textured textures thick thin wallpaper aged burn damage damaged degraded grunge paint scar weathered decay design graffity grafitty graphic grungy urban decay blank copyspace corroded faded scratched sign yellow construction diamond element grating gray grille rack rhombus saavem clip art clipart gold illustration striped stripes scribbles impasto