Line the bottom of a cookie sheet with parchment paper.
Wash kale and use a salad spinner to remove the excess water.
Cut or tear the leaves into "chip" sized pieces, removing the tough stems as you go.
Put olive oil and kale into the gallon freezer bag, seal (with air inside), and shake vigorously.
Place kale on top of the parchment paper, in a single layer on the baking sheet. Sprinkle with ranch seasoning.
Bake until crispy, about 15-20 minutes (cooking times seem to vary depending on variety of kale etc.), checking periodically. They should have just a hint of brown on the edges.