Films are commonly used in snack food packaging due to their excellent barrier properties, durability, and versatility. The specific type of film used for snack food packaging may vary depending on the specific requirements of the product, but some common options include:

1. Polypropylene (PP) film: This is a popular option for snack food packaging due to its high clarity, durability, and resistance to moisture and grease. It is often used for products such as chips, crackers, and nuts.

2. Polyethylene (PE) film: This is a flexible and cost-effective option for snack food packaging. It can be used for a variety of products, including popcorn, pretzels, and candy.
   

3. Polyethylene terephthalate (PET) film: This is a transparent and strong film that is often used for packaging products such as candy and baked goods.

4. Nylon film: This is a high-performance film that is often used for packaging products such as potato chips and other snack foods that require a high barrier to oxygen and moisture.

5. Metallized films: These films are coated with a thin layer of metal, typically aluminum, which provides a high barrier to moisture and oxygen. They are often used for products such as popcorn, snack bars, and jerky.

In addition to their barrier properties, films used for snack food packaging can also be printed with high-quality graphics and branding, making them an effective marketing tool. They can also be produced in a variety of sizes and shapes, allowing for flexibility in product design and packaging. Overall, films are a versatile and essential component of snack food packaging.