Plus zinc cents have an advantage when the coin press machine isn't adjusted quite right and solid copper coins are 'rolling short'.
On the other hand, zinc pennies might be preferred if you want to use a coin dated the same year as you pressed it. Copper plated zinc cents may also show some silver streaking when the thin copper plating is broken.
Post 1982 zinc cents were made of copper plated zinc and can be tricky to clean. Glad you asked! :-) Pre 1982 solid copper cents are preferred by most elongated coin collectors. Which cents work best in a penny press machine?
