I reckon just drawing a picture of young James on the envelope would almost see it to his door ;).
On a more serious note, Ed, perhaps having a spare sheet of paper under your writing hand may save you some ink stains. I remember reading of such a technique somewhere, though I can't remember just how that spare sheet should be positioned to prevent the smudging of the already written work. I'm fairly certain that was it's main reason of use all the same.
Mick