A team's sprint board needs to radiate information about how the sprint is going. Fridge magnets for use on a team's magnetic sprint whiteboard can be custom printed. The trick is to print "business card fridge magnets" for only ~AU$10 for 10-20 cards. Vistaprint (I have no commercial benefit) provides a great service of uploading your card image (e.g PNG) and printing it.
I've found these magnetic card reusable using whiteboard markers. For magnetic tags like "BLOCKED" or team member names, create a card with many tiles and cutout the tiles when delivered (See example below).