I seem to recall that some guy got the World Record for tiniest writing by writing something like an entire book of the Bible on the back of a postage stamp. I've been trying to find info about this. What book was it (or was it only a portion like the Sermon on the Mount)? It seems that a number of people have been able to write the Lord's Prayer or the Ten Commandments on a postage stamp, so that's probably not World Record worthy.
Anyway, if you have any recollection of this or can find it where I've failed, I'd be much obliged. Doesn't have to be in Logos. Google would be fine too. In fact, I think Google will be a necessity. I only found a few hits for "on a postage stamp" in Logos (none for "on the back of a postage stamp" or "on the back of a stamp"), and none of them had anything to do with tiny writing.