A repetitively reusable envelope closure arrangement including a pair of thin magnetic plastic patches attached by a cementing agent to at least one portion of the foldable flap of the envelope and to at least one corresponding portion of the envelope body in contact therewith such that the flap is magnetically secured in a closure position. In an alternative embodiment, finely powdered magnetic material having a high order of magnetic retentivity is magnetized in the fluid medium of a standard gum and applied to at least one of the aforementioned envelope flap and body portions and a similar mixture of low retentivity magnetic material particles in gum is applied to the corresponding mating flap or body portion to effect a magnetically secured closure.