These results can be related to several important factors that influence ballistic resistance, such as relative density, laminate design, and fracture stress. Although the relation between the density of the glass and polymer (i.e., PC, PVB, PU) and the ballistic limit velocity (V50) as a function of the stacking sequence has been researched to improve protection performance [16e18], there are only a few studies on the fracture behavior and protection perfor- mance of strengthened soda-lime silicate (SLS) and borosilicate glass. Various parameters have to be considered in order to deter- mine the ballistic impact resistance as a function of the various properties of glass. However, determining the impact resistance becomes complicated owing to the additional machining, polish- ing, and strengthening that occur before lamination of the mate- rials. Also, it is very difficult to strengthen large sizes of glass (310 310 mm) such that the glass satisfies the standards outlined by the National Institute of Justice Standard (NIJ-STD-0108.01) on a smaller laboratory scale. However, the mechanical properties, including Vickers hardness, fracture toughness, and flexural strength, are important factors in terms of ballistic performance, and they influence crack initiation and crack growth resulting from ballistic impact.