Apart from just looking cool on your desk, wax seals are great for adding some nerdy flair to your science-themed wedding or graduation party invitations. If you're thinking of using seals for a large number of letters, invitations, special announcements, here are some of the things we learned in the process of doing our own. When Geoff and I got married we used wax seals to seal our wedding invitations and we learned exactly what NOT to do first hand... and how to make it work.
First, it is absolutely possible to use the wax seals we sell for sealing large numbers of letters (in fact we totally recommend it; they look awesome!), but I would strongly advise that you do not try to use the candle style wax sticks like the ones that are included in the kits. For a few seals, the candle style wicks are great, and the process is fun, but if you are going to be doing tens or hundreds there is absolutely a better way.
We would recommend getting yourself a hot glue gun (if you don't already have one) and some sticks of wax that are glue gun-ready. We're working on making some of these supplies available in our shop, but until then, they're pretty easy to find online.
Using a glue gun is a lot less authentic (and you won't feel as much like you're sealing a scroll for your raven to take to your friends in the North) but it will mean that you don't have to wait for a flame to melt the wax one drip at a time, end up getting bored, start dripping wax everywhere after the 10th seal and then start cursing the day you decided to make your letters so fancy. If you are hell-bent on authenticity, (which Geoff sure appreciates), we would recommend you get a lamp oil melting set, or a melting pot (video link). With one of these sets you heat up chunks of wax in a spoon over a flame. It's still slow, but its 5x faster than using a candle style wax stick. Otherwise you can melt a whole bunch of wax beads at once in an electric melting pot.
We tried doing ours all with the candle style ones... and we vowed that if we were to do this again, we would most definitely use the glue gun method. It gives you the same exact results, it's easier, plus it's cheaper.