Where do you authenticate a baseball?

Answer 1

An autograph that is not authenticated by a creditable company could sell at half the market value or less. Two of the top, and most trusted authenticators are PSA/DNA, and James Spence Authentic (JSA). Collectors will pay more for signatures authenticated by either one. It may sound odd but in some cases PSA/DNA, and JSA authenticated signatures may sell higher than a Letter of authenticity from an unknown or less trusted authenticator that witnessed the signing even though PSA/DNA, and JSA did not. It's just a matter of collectors trust, and collectors will pay more for it.