Using a knife, trim the thick ribs from the leaves. Discard ribs. Cut kale leaves into desired size chips (note: they will shrink while baking).
Rinse the cut kale under water. Dry VERY well with paper towels.
Combine vinegar, oil and 1/4 tsp of salt in a large bowl. Whisk. Add kale pieces.
Use your hands to “”massage”” the kale for 1-2 minutes until soft and bright green.
Spread the kale in a single layer on a foil or parchment lined baking sheet. You may need 2 or 3 baking sheets.
Sprinkle with remaining salt.
Bake for 7-10 minutes, turning after 5 and removing pieces as they turn brown and crunchy. Largest pieces should take the full 10 minutes, smaller pieces may take less. Serve immediately.