This is a quick fridge magnet I drew up that uses 6mm round by 2mm thick magnets that are completely inside the print, non visible from the back side.
Stop 1st layer after 4.0 layer height
Insert 6 - 6mm round by 2mm thick neodymium magnets
Resume print then stop again after 5.0 layer height
Change filament to 2nd color and resume print to make the letters and heart a different color than the cheese.