WestSoy is one major soymilk producer that uses Tetrapak. In stores like Sprouts and Trader Joe's it's often the only soymilk available. Tetrapak is nice in that it doesn't need to be refrigerated until you open it, but it's made of paper with a layer of foil underneath it cannot be recycled.
Tetrapak can be recycled, though depending on where you live it may or may not actually be recycled. It's certainly more involved than recycling, say, glass.
