pop art, polka dots, circles halftone, comic effect pattern

1960s 1980s 60s 70s 80s andy art circle comic cover culture dot dots dpi duotone effect fade gradation gradient half halftone lichenstein lichtenstein pattern pointillism pointillist points polka polkadots pop popart poster raster red retro seamless speckle spot stipple stippling tone vector vintage warhol warhole yellow