1. A label forming method, comprising: while transporting a base sheet having a print surface by a first transportation mechanism, forming a first pattern on the print surface and forming a marker at a prescribed position on the print surface; transporting the base sheet to a second transportation mechanism, the base sheet being transported by the first transportation mechanism and with the first pattern and the marker formed thereon; detecting a position of the marker on the base sheet; determining a position of the first pattern based on the prescribed position on the print surface and the detected marker position; deriving a position to form a second pattern according to the determined position of the first pattern; and while transporting the base sheet by the second transportation mechanism, forming a second pattern at the derived position.