Does clear coating affect the value of an autographed baseball?

Answer 1

No CoatingYes especially with newer baseballs. It will hurt the value of the signature. Years ago it was a common practice to shellac the Baseball to protect the signatures. This practice stopped when it was realized that the balls would turn yellow, crack, and peal off. With some of the earliest signed baseballs, the value is not hurt as much as with newer balls because the Autographs are more rare, and it was common.