abstract appearance Australian background bare bark brown colors colours cracked cracks cream dry edge edges eucalypt eucalypts gnarled gray grey grooves layers lines mottled peeling rough self-shedding shadows shapes shedding smooth sunlight surface texture textured textures tree tree trunk trunk uneven variations wallpaper wood branches bumps close-up cut-branches patterned patterns perspectives ridges shape shaped strange surfaced surfaces timber tree-trunk twisted unusual varieties architectural decorative Designs details distinct distinctive edged exterior external fancy interconnected interlinked light linear lined mosaic rectangular slabs stone stonework strength style thick thin variation varied various wall dip Dirt dust dusty mollusc mollusk pearly pitted ridge rim seashell sharp shell spiral spiraling spiralling turban shell turns twists colorful colourful fitted interior internal angles