Autographed "Buyback" 2017 Upper Deck Thor: Ragnarok Precious Metal Gems Purple “Thor” autographed by Chris Hemsworth in Blue Ink at the 2019 ACE Comic Con Midwest and authenticated by James Spence Authenticaton via their JSA WPP (Witnessed Protection Program). All signed items come with JSA WPP Certificate Of Authenticity with matching serial-numbered sticker on card.