Preheat oven to 225 degrees F. Line 2 large (17 x 11 inch) baking sheets with parchment paper or silicone baking mats.

Cut off the ends of the zucchini and slice them very thin (about 1/8 inch thick), making about 5 cups of zucchini slices. To make it easy and consistent, use a mandolin or the slicing attachment on a food processor.

In a large bowl, add the oil, vinegar, salt, and pepper. Whisk until well combined.

Add the zucchini to the bowl. Use your hands to very gently coat the zucchini in the vinaigrette.

Pull zucchini slices from the bottom of the bowl (to ensure even vinaigrette distribution) and lay them on the baking sheets. Spread them out into an even layer, not overlapping.

Bake until the zucchini is brown and crisp. When you lift the zucchini from the baking sheet, it should not bend. This will take between 2 and 3 hours, depending on how thin your slices are and the color of your pan. If some chips seem done while others still seem a little soft and soggy, remove the chips that are done and return the baking sheet to the oven until all the chips are crisp.

Cool completely. Store in an airtight container.