The differences are minor: for example, Stax are thicker and are less prone to breaking in the package. The shape of Stax is a simple curve, while Pringles are formed into a double-curved saddle shape. Stax are also gluten free, while Pringles contain wheat starch. Stax are packaged in recyclable plastic packages , while Pringles are packaged in cans consisting of cardboard and metal, which are not as readily recyclable.
In Brazil they are on the market under the brand name "Elma Chips Stax" since late 2006 in the flavors "Cheddar", "Sour Cream & Onion" and "Original" (Regular). Elma Chips is a Brazilian brand of Pepsico Inc, also known for "Stiksy", among others. The yellow lid is marked with "Lay's Stax". In Venezuela, they were introduced in early 2007 with the flavors "Cheddar", "Sour Cream & Onion" and "Natural Flavor"