The problems that you might face with your business card would have less to do with deciding what to add to the card and more to do with how they are going to fit in this erstwhile limited and cramped space.The more information you add to your business card, the more effective it would end up being for you, but you only have about seventy square inches to work with once all has been said and is now out of the way.
Hence, it might be incredibly useful for you to stop printing out the entire names for the social media handles that you have on your Metal Kards and instead go for logos or alphabets. For example, if you are displaying your Instagram handle on this card, which you most definitely should since it can give it more weight than might have been the case otherwise, you would be better off marking it with a logo or the letter I instead of typing the whole thing out which would end up taking three to four times more space.
We feel like this is the best way to list your handle since other methods can make your card look like a wall of text. Anyone that looks at the card would be liable to get overwhelmed by the sheer quantity of information that is screaming at them, and giving various elements of your card a bit of breathing room and free space can help reduce the chances of that happening. Indeed, switching to a logo based representation for your handle can virtually eliminate the likelihood that someone or the other might find your card to be unpleasant.