Signature education is essential when collecting. What is also essential is knowing that many will say that a signature is authentic without having that proper education. A piece of paper with "Certificate of Authenticity" on top does not mean that your book has an authentic signature. The most important thing to do when looking to acquire a signed Potter book, or any book for that matter is to RESEARCH. There are collectors that study nothing but Rowling's signature and have become masters at identifying her authentic signature. Two of those masters are The Potter Collector (Peter) and All the Pretty Books (Carly). If you have a question on whether or not a signature is authentic, or you are interested in purchasing what you think to be an authentic signature, please reach out to myself, Peter, or Carly.