Adhesive envelope for a shipping label or the like

A method for mass producing a plurality of separate, identically-shaped adhesive envelopes of the type employed in attaching an insert to a container surface and the like, said method comprising the following steps:

• positioning a plurality of separate strips of plastic material side-by-side on a continuous sheet of plastic material, wherein each strip of plastic material is spaced from adjacently disposed strips of plastic material;
• attaching strips of adhesive material to portions of said continuous sheet of plastic material extending between confronting sides of said adjacently disposed strips of plastic material, wherein each strip of adhesive material has an adhesive surface facing away from said continuous sheet of plastic material;
• forming aligned openings through a plurality of said strips of adhesive material at preselected intervals corresponding to substantially the uniform width of each resulting envelope;
• simultaneously heat sealng a plurlity of said strips of plastic material to said continuous sheet of plastic material along a surface extending between said openings, in a direction substantially perpendicular to said strips of adhesive material;
• simultaneously cutting through a plurality of said separate strips of plastic material and said attached continuous sheet of plastic material along said heat sealed surface;
• and
• cutting through each layer of adhesive material and attached continuous sheet of plastic material along a line extending between adjacent openings formed through said respective layer of adhesive material to separate said envelopes from one another.