abstract appearance background bark close-up colors colours dry edge edges gray grey grooves layers lines patterned patterns perspectives ridges rough shape shaped shapes strange surface surfaced surfaces texture textured textures timber tree tree-trunk trunk twisted twisting uneven unusual variations varieties wood Australian bare brown contours cracks cream gnarled Melaleuca mottled paper-like paperbark paperbark-tree peel peeling shadows shedding soft strips sunlight wallpaper cracked eucalypt eucalypts self-shedding smooth tree trunk