I'm knitting a sweater that needs 5 buttons but I couldn't find any I liked at the fabric store. But I do have some Irish coins from a trip and I think I can make my own buttons by molding and then casting the coins. The same way I copied the bonefolder.
I used a putty mold which comes in 2 colors you knead until even. Then press the coins and wait 20 minutes. I mixed the liquid plastic and then cast. Too many bubbles! Redo! Remold then cast again. After it solidifies pop out and sand off the excess. Crap, sanding takes too long and I need a lower grit. Take misshapen coins to the cement patio and use that to get the extra off. OK now notice all if the coins are thicker on one end. Oops with the molds, is there a teeny level I can buy?
Paint! Multiple layers then sand off enough to show the designs. Punch holes for sewing. Profit. If anyone uses this method to counterfeit coins, seriously, is that the highest denomination you can come up with? Good luck ransacking candy machines.