Abstract: A panel fastener system is provided for securing a panel sheet to a frame across an opening, e.g. window opening. The system comprises a frame member mounted along the length of the frame and having a first magnetic element non-adhesively mounted to the frame member. A panel sheet is provided of suitable size to cover the opening. A panel retaining member extends along is mounted to the edges of the panel. The retaining member has an outer and an inner leg connected to each other at one end, the edges of the panel being retained and mounted therebetween. A second magnetic element is non-adhesively mounted to the inner leg. The first and second elements are magnetically attachable to each other. The inner leg and second magnetic element mounted thereto are both shaped and mounted to each other to form a rigidized elongated hollow structural member therebetween along the length of the edges of the panel.