In Season 2, the White Tulip was established as a sign from God that Walter was forgiven for his past actions.
While not paper, the team follows a series of Beta tapes hidden in amber by Walter to reconstruct the plan step-by-step. FRINGE Recap: 'The Recordist' - Give Me My Remote Fringe - Season 5
Early in the season, Walter finds a large sheet of paper filled with equations—the original plans for the machine to defeat the Observers—hidden in his lab. In Season 2, the White Tulip was established