Gravity Falls: Journal 3

 is the official real-life canon Journal 3, containing information from the show, with the author's research and Dipper's and Mabel's notes. The book was released on July 26, 2016.

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!''

Synopsis
Hey, guys!

I'm Alex Hirsch, the creator of Gravity Falls, and the voices of Grunkle Stan, Soos, Bill Cipher, Old Man McGucket, and possibly your nightmares.

If you're a fan of the show, or just someone who likes to be confused, delighted, and horrified (in that order), then you're in luck! In your hands you hold the Author's coveted journal, a full-color 288-page treasure trove of never-before-revealed secrets, monsters, and mysteries in the sleepy town of Gravity Falls. You'll learn Ford's tragic backstory, Blendin's whereabouts, what Dimension 52 is, and how to lure a "Plaidypus."

This is a book many dark forces want to get their hands on, so beware anyone who tries to take it from you (especially if they have glowing yellow eyes)!

Most important, have fun. After all, there's no such place as Gravity Falls.

Or is there?

Your pal, Alex Hirsch

Special edition
Due to the success of Journal 3, Disney publishing will release a special limited edition of the book on February 14, 2017.

Description
"A limited edition Untie the string and unwrap the brown paper to reveal . . . Journal 3 Limited Edition! This 288-page book contains all of the content of the regular edition, plus all-new top-secret black light pages on real parchment; a cover with leather texture and shiny metallic pieces; a magnifying glass; a tassel bookmark; and removable photos and notes. This $150 limited edition, with only a total of one thousand numbered copies, will also include a signed note from the creator of Gravity Falls and co-writer of Journal 3, Alex Hirsch himself."

Secret messages

 * See: List of cryptograms

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 (semicolon shown 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."
 * The Journal has Dipper's notes from every episode except "Dipper vs. Manliness", "Little Dipper" and "Bottomless Pit." The last two might be because the book already has entries on the Height Altering crystals and the Bottomless Pit.
 * At New York Comic Con in 2016, it was revealed that limited edition copies of the journal with the invisible ink will be made available due to the success of the regular copies. Release is set for February 14th, 2017.