A packaging apparatus includes a flexible insert and a sealable wrapper. The flexible insert includes: a body having a first face and a second face opposite the first face; a first flap at a first edge of the body; and a second flap at a second edge of the body, the second edge located opposite the first edge. The sealable wrapper includes: a first panel; and a second panel. The sealable wrapper is sized to enclose the flexible insert. The first face of the body of the flexible insert is configured to engage the first panel of the sealable wrapper upon insertion of the flexible insert to the sealable wrapper. The first and second flaps are configured to, upon the insertion, swing from the body of the flexible insert to engage the second panel of the sealable wrapper such that a thickness of the packaging apparatus becomes substantially uniform.