abstract background brown crack cracked cracked wood dark wood decay design dry wood old texture wood board cracked wood knot knot knot hole knot on wood wood knot wood texture beam cracks rugged weathered wooden knot rough timber lumber plank split textures wooden chopped natural nature organic pattern aged angles appearance color colors colour colours cracking damage damaged deteriorating disused dry-wood grained grains gray grey lines maintenance rustic splitting surface surfaces surfacing textured upkeep wood-grains worn