We do them all the time. You need a jacket hold-down and need to flash the jacket before printing to tighten it up. Also, you can't print over seams. Obviously, the print won't be as crisp as on a t-shirt, but most companies that want Carhartt jackets printed want it cheaper because their employees use the jackets rough. If the jacket is a rain resistant, I add a little nylon catalyst to the ink for adhesion.