The club has professionally made hard plastic badges, but the class has paper badges that go into clear plastic badge holders.
We've been using the pin-back badge holders for a long time, but recently we tried the slightly more expensive magnet backed ones, and people really liked those.
If the badge holders break, or get lost, or there aren't enough of them, we need to buy more.
There are latex templates for making class badges in the athena locker in /mit/tech-squares/club-private/badges
Those put the Tech Squares logo in the corner and are what we've traditionally used and are very nice and all, but there are two big caveats:
People have said their biggest problem with the badges is how readable the first names are from far away. The font used in the latex badge template can only be enlarged somewhat before it doesn't fit. Other fonts can fit much better. We experimented with MS Word and various fonts and the longest name until we found one that was the most readable from a distance, and then we increased the size of the font even further for people with shorter names, and got the names to be much much larger.
If the size of the badge changes at all you have to adjust the latex document a lot, and it seems like the company that makes the badges changes them every year, and at that point the ready made latex templates aren't much use since it would be easier to hack at it in a word processor if you're not a latex expert.
So my advice is to do your own thing with the badges.