Abstract: A blast protecting panel for interior portions of building windows includes a blast-shielding panel of a high tensile fiber woven in an open weave fabric in such a manner whereby a high degree of light is transmitted through the fabric while still allowing see-through visibility. The fabric is mounted using a retention system, which can be either fixed or dynamic, allowing the fabric to unwind and billow out into the building, retaining flying glass and debris. The retention system preferably includes fixed upper and dynamic lower tension retainers around which a length of fabric is wound and which allows the fabric to unwind therefrom without becoming detached from the retainer case or from the surface to which the retainers are mounted.