250GSM is nowhere near average and your printer doesn't support above 216GSM cover.
~75GSM is average plain bond paper, your printer is expected to jam on stocks it doesn't support.
From this forum I have mastered how to use the by pass tray, now I need to know how to priont on card. Everytime the card goes through is jams. Its not even very thick, its 250gsm, ,which is average. Any ideas on how I can get it to print please?