I write it down and send it in a letter to myself. Address the envelope on the back, so the stamp and PO seal crosses the the evelopes flap. Don't open it when it lands. It comes back it's got a Royal seal with the date on it.

Dunno if that works in countries without a monarchy.

I wonder if that works in Canada, post office usually seals it across the stamp.
Well 30-40 bucks is not too bad if you have an album worth just as a backup.