Pringles are reconstituted potatoes = i.e. mashed and re-shaped to mimic the thinly cut chips.
[edit] They're not even whole potatoes.
Pringles have only about 42% potato content, the remainder being wheat starch and flours (potato, corn, and rice) mixed with vegetable oils and an emulsifier
Exactly. They taste ok I guess, but they are not potato chips!

KT