What's the difference between rollstock film & premade bags?

What's the difference between rollstock film and premade bags?

Knowing the packaging material format you require informs which machinery the equipment manufacturer recommends.

Here are descriptions of two major flexible packaging formats:

Rollstock film is a long, flat sheet of (usually plastic) packaging material that is wound around a hollow core. It is usually pre-printed with graphics. This large roll of film is loaded onto the back of a form fill seal machine which then forms it into bag shapes, fills the bags with product, and seals them shut. Rollstock film is generally economical in cost per bag and can run at high speeds.

Premade bags arrive at the packaging facility already formed into their end bag shape. They are loaded into a pouch fill and seal machine that fills them with product and seals them shut. Premade bags have a premium look that can't be beat, but usually cost more per impression than bags created from rollstock film.