Wash the potatoes first, and then peel them. Peeling is not necessary; it is a personal preference. Next, slice the potatoes to around 1/8 inch thick using a sharp knife or slicer. Make sure to place your sliced potatoes in a bowl of cold water to avoid oxidation, as potatoes tend to turn brown quickly.
The next step is to blanch the potatoes. Boil a large pot of salted water, throw in your sliced potatoes, and let them blanch for about five minutes. While the potatoes are blanching, take a large bowl, and fill it with ice water. Once the potatoes are done blanching, place them in the bowl of ice water for about 15 minutes. Then, remove them, and dry them with paper towels.
The next step is to place the sliced potatoes onto a baking pan or cookie sheet. Apply vegetable oil on the baking pan or cookie sheet to prevent scorching. Then, place them in an oven. Make sure that the oven is at its lowest temperature, and leave the oven door slightly open to allow air to circulate and moisture to escape.
The other option is to use a dehydrator to dry the potatoes. Place the potatoes onto the racks. Apply vegetable oil on the racks before placing the placing the potatoes. The potatoes are dehydrated when they are translucent and crisp.