Clear coat\sealant?

[laurakrycek.livejournal.com]

I've done some painting on boxes and other things, but my paints always seem to stay just a little bit sticky. Is there some kind of clear coat I could put on over the paint that would dry non-sticky? It's a pain when you work really hard on something, but then every time you open the box, the paint peels off a little more. I thought about dusting it with some kind of powder, but don't want to alter the color. I haven't used Modge Podge or any of that stuff, so I don't know how that works. I've used Sculpt Or Coat because I got a bunch free at a technical theatre convention (USITT, if there are any techies here) and I love it, but was hoping for something more readily available and that I could just run to the store and pick up rather than having to order online. Thanks!