Baked Kale Chips

"For such a sturdy and hearty vegetable when raw, this leafy green dehydrates and becomes almost delicate when cooked at a low temperature. For baking, you have two options: You can bake the kale on a cooling rack, which results in less crispy but sturdier chips. Or, you can bake it on a silicone-lined baking sheet, which results in optimum crispness but a more fragile product (you'll have to be careful when removing it from the baking sheet). Either way, this snack is quite addictive...."