What is the Best Ice Pack for Coolers? Trying to figure out what makes the best ice pack for coolers? One question we’re often asked here at Cooler Shock is about the packaging – why do we use our flexible bags rather than making hard-sided ice packs. The answer is pretty simple: we’ve spent a lot of time engineering the best container for the job.
Rigid ice packs usually have a shell made of HDPE (high density polyethylene) or of polypropylene. These are both fine materials: they’re cheap, they keep everything in one shape, and they contain stuff reliably.