PUR (Polyurethane Reactive) is the strongest, most flexible book binding adhesive available. It offers superior page-pull strength compared to standard hot melt binding adhesives, averaging 40 percent to 60 percent better page pulls than traditional adhesives. This makes PUR ideal for heavy-use applications or projects with heavy ink or coating coverage. PUR is considerably more flexible than standard EVA hotmelts, giving the finished product the ability to lie flat when open, allowing for hands free reading.