abstract architectural background barrier basic 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 white blue adhering backdrop cracked cracking cracks curved drill-holes modern mottled perspectives rectangular smooth split splitting variation wallpaper well-built cement dark surfaced traditional-brick-wall walled