Nontack pressure activated adhesive

A pressure activated adhesive system comprising:

• a pressure sensitive adhesive layer having a nominal thickness and at least one side having a nominally flat active surface;
• a multiplicity of discrete hard barrier structures on the active surface of said adhesive layer, each of said structures having a length of at least 0.00025 inch which projects from the active surface a distance in the range of about 0.00025-0.0005 inch, said barrier structures in the aggregate, occupying about 10-30 percent of the area of said one side of the adhesive layer.

A pressure activated tape or roll system comprising:

• a release liner having outer and inner surfaces;
• an adhesive layer having a pressure sensitive surface confronting the inner surface of the release liner;
• a multiplicity of discrete hard material units each having a nominally flat surface in direct contact with and releasable from the inner surface of the release liner and a substantially opposite surface permanently adhered to said pressure sensitive surface, each of said units having a length dimension extending at least about 0.00025 inch from the pressure sensitive surface of the adhesive layer toward the release liner.