Every time an electric vehicle accelerates, the steel sheets stacked inside its motor flip their magnetic orientation ...

Another option would be to print full-page laser printer labels, roughly cut out the image you want on a magnet, affix to a magnet sheet and trim again.

You may have heard of “EMI suppression” or “RF antenna” sheets, which are thin, flexible magnetic shields. Maybe they have been seen laying around the laboratory, typically black or gray in color, but ...