An article (600) is provided which includes a body (500) having an interior volume (100), and hook (124) and loop (125) features which, when pressed closed in at least one locations (130, 131) location, creates a dynamic hammock dam (132) that retains a fill material (140) that has been inserted into the interior volume. The strength of the hammock dam increases with outward pressure (141) applied on the closure by the fill material. The article is preferably equipped with a large mouth opening (110) which allows rapid filling or emptying of the fill material from the internal volume.