abstract appearance architectural architecture background basic brick brick-wall bricks color colored colors colour coloured colours crack cracked cracks exterior external rough smooth solid standard strength surface surfaces texture textured textures uneven variation varied various wall wallpaper angles brown building contrast contrasting corrosion corrugated corrugations dark decay deterioration elements metal old perspectives rust rusty variations wearing weathering bark close-up dry edge edges gray grey grooves layers lines patterned patterns ridges shape shaped shapes strange surfaced timber tree tree-trunk trunk twisted twisting unusual varieties wood conglomerate granite green growth life macro moss moss-covered plants rock rocks sprouting craked