Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Wash the potatoes thoroughly, then use a mandoline or sharp knife to slice them very thin—about 1/16 inch thick or less for maximum crunch.
Transfer the sliced potatoes to a large mixing bowl, then drizzle with the vegetable oil. Gently toss to evenly coat each slice with oil—this will help them crisp up in the oven.
Spread the oiled potato slices in a single layer on the prepared baking sheet, making sure they do not overlap for even baking.
Bake in the preheated oven for about 15-20 minutes, watching closely near the end. The chips should turn golden brown and become crispy around the edges, with a satisfying crackle when you lift them.
Remove the baking sheet from the oven and let the chips cool for a few minutes—this will help them firm up and become even crunchier.
Sprinkle the warm chips with salt to taste; toss gently to distribute evenly.
Enjoy your homemade oven-baked potato chips immediately for the best crunch, or store in an airtight container for later snacking.