I like this. Is it legal?

Ironically, we did penny tile in both of our bathrooms. As to the “how” of this project, you can get mesh backing that’s adhesive on one side. Stick all the pennies to that, in 8” or 12” squares, then lay it down in grids like any other tile that’s similar. Grout it & voila! Pretty cool effect, but the anal retentive in me badly wants of them heads-up & facing the same direction!

This reminds me of a story… In colonial Venezuela, a very wealthy and eccentric nobleman, whose name I can’t recall, in order to effectively display his wealth and eccentricity did the exact same thing: he paved the whole floor of his manor’s ballroom in doubloons. It was so impressive that it became known all across the Spanish empire, and eventually even the King of Spain himself learned about it. He immediately gave orders to undo such thing, and the nobleman had no choice but to comply. The King didn’t want his face, depicted in the coins, to be stepped on in such manner.