The present invention relates to an envelope, a bag, and a pack and, more specifically, to a pack which enables users to simply and quickly seal the entrance after putting a storing object into the pack. According to the present invention, the pack facilitates the opening and closing of the entrance of the pack which stores papers without an adhesive or additional tools.본 발명은 봉투, 봉지 등 봉투에 관한 것으로, 더욱 상세하게는 내용물을 투입한 후 간단, 신속하게 투입구를 밀봉할 수 있는 봉투에 관한 것이다.
