White Gate

The White Gate is a scrap found in Paper Mario: Sticker Star. Mario is required to retrieve it by Hammering the tree branch at the easternmost point of Whammino Mountain to cause a chain reaction which flings the White Gate to an area Mario can reach, and backtracking to it.

Mario must then travel east to the empty spot where the White Gate was and paperize it back into place, allowing entry to the shop area beyond it as well as the Comet Piece.