In fact, there's another method. By pulling red copper through a small hole, it will automatically become copper wire.
Similarly, pulling a copper board through a three-millimeter-wide seam will reduce it to three millimeters thick.
Use mechanical force to pull.
This seam is relatively easy to adjust and reinforce, and won't deform during the processing of the copper board.
Although three millimeters thick is a bit too thick, people of this era probably wouldn't mind.
A three-millimeter-thick coin.
Close to two centimeters in diameter, made from red copper, such a coin should be well-received.
But then again, he doesn't actually own a copper mine.
If he were to use the previous method, pressing the copper board between two metal plates to just the right thickness of two millimeters would be extremely difficult. However, if the size of both the metal and copper plates were reduced, it could still be done.
