Procrastinating my writing by way of typecasting...
Yes, I've been wondering how the typed postcard thing worked out. Sounds like you've opted for handwriting.Or, maybe you could type on adhesive labels, which can come in full-sized sheets, cut out the typed message and apply to the postcard!
If the ink is dry--test it with some blotting paper--you can "seal" your work by rubbing a candle across it. I do this all the time for the addresses on envelopes that are done with fountain pen. Works great. Just make sure the ink is dry first and then gently rub the wax candle across the area you want to waterproof.
Wordherder, you beat me to it! I have a piece of beeswax that I use for this. Deek, be sure the ink is well and truly dry or the rubbing movement will smear things. I sometimes use this on my typewritten addresses as well - just cause I fret about these things! ;-)
cool, i learned something! The bigger machines can roll postcards. Also try rolling them in from the front. I mean next time.