abstract architectural background barrier basic blue brick brick-wall bricks brickwork building building-material colored coloring colors coloured colouring colours composite constructed exterior external fading firm linear lines mortar old partial partially-painted perspective rough secure security solid standard strength strong style surface surfaces symmetry texture textured textures uneven varied various wall adhering backdrop cracked cracking cracks curved drill-holes modern mottled perspectives rectangular smooth split splitting variation wallpaper well-built artwork blocks fitted large layered layers painting porous rock rock-wall rugged sandstone sedimentary-rock shade shadows shaped stone stonework sunlight sunshine variations weathered weathering cement dark surfaced traditional-brick-wall walled