Printable sleeve envelope and method of forming same

A printable sheet includes a blank for an envelope having a central body panel, a top flap, a pair of opposing side panels, and a bottom flap. The envelope blank is capable of being removed from the printable sheet and folded along weakened lines to form a secure sleeve for holding various items. The sheet on which the envelope blank is formed is capable of being placed in a printer to have images and/or indicia printed thereon. The envelope may also include integral index tabs for indentifying and archiving the contents of the folded envelope. The top flap, bottom flap, and opposing side panels are adapted to interconnect to secure items in the envelope.