For a complete list of all 13 note locations, you can check the comprehensive Slender: The Arrival Guide on Steam. Slender: The Arrival - The Complete Guide (2016)
: Located in the bathroom near the radio, past the kitchen.
: Located on a box inside the cave before the final radio tower sequence. Significance of These Papers
were childhood friends who both shared sightings of the Slender Man.
While "deep paper" is not an official term in , it likely refers to the 13 numbered Letters (Scrapbook items) that provide a "deeper" look into the game's lore compared to the standard eight pages found in the woods.
: Tacked to a pole on the playground slide in the backyard.