background bump bumpy floor tile wall wallpaper blur bump tiles grunge New York non-skid nubs NYC subway threshold urban yellow 3D abstract art backdrop black cage circles column curve decoration depth design distortion form futuristic geometric graphic grid groove heart illustration infinity lines op art pattern relief sci-fi science fiction scrapbooking shapes spot squares texture tiles twisted valentine warped weave white pink bulge dot space time walls blue distort hexagon mosaic op-art optical pop art round row twist vasareli vector warp brown hi res contour diamond square green vasarely