We all know that down becomes virtually useless when wet, but it is hard to find a lighter and warmer insulation out there. That is until now. The North Face believes they have come up with a synthetic insulation, called ThermoBall, that is better than down in almost every way.
ThermoBall synthetic insulation is designed to closely mimic the physical properties of down. Instead of coming in large fibrous sheets, similar to housing insulation, ThermoBall is made up of tiny strands of polyester that have been spun and frayed into 0.15-0.2 inch balls.
As the insulation balls are so tiny, The North Face can use smaller triangular baffles than they could with down, cutting out further fabric weight. The ThermoBall insulation floats freely inside the baffles, lofting like feathers, and leaving air pockets to retain warmth.
These tiny synthetic balls are as light, as flexible, and compress just as well as down with the added benefit of insulating when wet. The North Face claims that ThermoBall insulation has a 15% better warmth to weight ratio than regular synthetic insulation, though still not quite as warm as down.
The North Face Hooded ThermoBall Jacket will retail for $280 and be ready for Summer 2012.