The third main ingredient of seal ink, along with color and binder, is oil. Since the ink is oil-based, and not water-based, it can take quite a while for the ink to dry. Be careful after stamping your artwork with your seal as it can easily smudge. Because the seal ink is made using oil it will also be hard to clean off your clothes or anything else it gets on by accident.
I recommend waiting at least several weeks before having your artwork backed/mounted in the traditional Chinese way as it involves wetting your paper or silk and the color in the seal ink, especially poorer quality ink, may bleed. Some people recommend waiting several months.