Ok cool. I wasn't sure if Woodies were from specific mintages or if they were just random years. Is it considered an error?
I am not sure what you mean "specific mintages", but I would guess they are available in every year since '56 (that is 1856) through 1982 in cents. I doubt many consider them errors although sometimes they become so extreme that they laminate and that is an error.
I stopped saving modern one-sided wood, I was finding too many. The tough ones to find are the double-sided type in memorial cents.