I used to buy BU copper pennies by the rolls for pressing use. BU stands for Brilliant Uncirculated, which is a numismatic term. It means that these coins went straight from the Mint to you (or your dealer) without going through circulation. Generally you can expect MS60+ grade coins, where MS stands for Mint State and 60 is a coin grading scale out of 70. But as EC collectors, we really don’t care how many steps on the Lincoln Memorial is visiable before we smash the pennies. The purpose of buying BU pennies is to ensure you have shiny copper pressed coins, although I also like the brownish tone that makes the coins look older.
The problem with buying BU rolls is that not too many dealers carry them. The cheapest BU roll pennies costs about $2 to $2.50. The dealers makes a few cents selling you each roll and he had to dig through his stock room to earn that money. On the other hand, you end up paying 4 to 5 times for your material. Nobody loses, but it’s never a win-win scenario.
I used to live near a dealer who always has these rolls stocked up (although he had been slowly increasing his prices), so I never thought about the alternative. Then I moved to Maryland and decided to press over a hundred coins for half a dozen collectors.
I called up all the local shops and made a deal to pick up the coins on Friday. By noon on Friday, the dealer was a no show and I was getting desperate. My bus leaves in a few hours and there was no way I can find replacements. So I went to the nearest bank and asked for $15 worth of pennies. I picked out the pre-1982 pennies and cleaned them with ketchup and baking soda. When I was done, they looked pinkish and I was really worried that they won’t be up to snuff. But they turned out to be really pretty presses. The shine surpasses the EC’s pressed on uncirculated pennies. So now I’m converted 
You can probably get around 100 copper pennies out of $5 worth of coins. After sorting them out, put them in a small container and cover the coins with ketchup. Mix and let it stand for a few minutes, stirring occasionally. Wash out the ketchup and dump baking soda over the coins. Add just enough water to make a thick paste, and stir the coins and paste. Wash out the baking soda paste and dry your pennies. Don’t forget to wrap the remaining zinc pennies and return them to the bank.
