Engineers and designers are using glass in increasingly demanding applications such as stairs, floors, and bridges, large minimally supported facades and overhead glazing. The use of laminated glass in structural applications has become more recognized and preferred as safer choice to monolithic tempered or heat strengthen glass. Structural interlayers are stiff interlayers that increase the safety of the laminated glass by increasing the strength. There are two options when choosing a structural interlayer, Stiff PVB or ionoplast interlayer. Both interlayers provide improved post breakage strength and structural benefits; however, some significant differences in properties that affect the final laminate performance exist. Applications that require high temperatures above 30⁰C or long load duration’s, ionoplast interlayers perform the best. Ionoplast interlayers require some special processing to ensure optimum quality of the final laminate such as lamination to tin side of glass and fast cooling rate in the autoclave to prevent haze formation. In the case of multi-ply laminations, a primer is needed for proper adhesion to the air side of the glass. Recent developments in Ionoplast have greatly improved the lamination processability with improved adhesion to the air side of glass and haze less dependent on autoclave cooling rate.