When is a crisp, not a crisp?  When it’s a Pringle.  

Yes, according to Wiki, Pringles only contain 42% potato.

(That’s less than half of the content, the rest is wheat starch and corn and rice flour, all mixed together with vegetable oils and an emulsifier. Of course they call themselves potato crisps, because wheat, rice, corn and potato fried gunk wouldn’t sound quite as tempting.)