The 2018 Topps Clearly Authentic Auto Green 21/99 Paul Blackburn #CAA-PB Auto 6fs trading card is a highly collectible item for fans of sports trading cards. This particular card features an authentic autograph of baseball player Paul Blackburn, adding to its value and appeal to collectors. With a limited edition of 21 out of 99, this card is in near mint condition or better, making it a prized possession for any avid collector of sports memorabilia.