Gravity Falls: Journal 3

 is the official real-life canon Journal 3, containing information from the show, and Dipper's notes. The book is set to release on July 26, 2016.

Title description
''Journal 3 brims with every page ever seen on the show plus all-new pages with monsters and secrets, notes from Dipper and Mabel, and the Author's full story. Gravity Falls fans will simply love this 288-page full-color jacketed hardcover version of Journal 3! Plus, the book jacket doubles as an exclusive poster!''

Trivia

 * Before the official title of the book was revealed, it was referred to as Dipper's Journal during the "Gravity Falls revealed" panel at New York Comic Con in 2015.
 * Promotional cards for the book's release were distributed during the "Gravity Falls revealed" New York Comic Con in 2015. Additionally at Comic Con, previews of the Gnomes and Leprecorn page were shown.
 * There is a cryptogram on each of the cards (semi colon to separate cards), "D VKRRWLQJ VWDU PDB IDOO; FUDFNV DUH KLGGHQ LQ WKH ZDOO; RQH HBH ZDWFKHV DOO." Once decoded using the Caesar Cipher, it reads, "A SHOOTING STAR MAY FALL; CRACKS ARE HIDDEN IN THE WALL; ONE EYE WATCHES ALL."