The sealing device for a paper-based container has an elongated release base member with a double-sided adhesive layer on a major side along the length of the release base member. The release base member is adhered to a front portion of a flap of the container by the double-sided adhesive layer so that the flap may be used to seal the container. To open the container, a pull strip of the release base member is pulled off and the flap is separated. To reuse the container, a second sealing device is applied to another flap of the container so that the container may be reused.