This will burst your bubble. Sealed Air, seller of the original stuff since 1960, is rolling out an improved — disappointingly unpoppable — variety. The new iBubble wrap takes up one-fiftieth as much space, saving on transport and warehouse costs. Packed in flat rolls, shippers inflate it themselves, and the redesigned shape aligns bubbles in a chain, making them more resilient. The company has struggled in recent years and aims to reinvent itself in a ballooning delivery market. But die-hard fans may send the new pop-resistant stuff packing.