Most poly 3‑prong folders are made from polypropylene, a durable plastic. Product listings typically appear as either "Material: Polypropylene" or generically "Material: Plastic."
Most listings cluster around letter size. Typical dimensions are roughly 11.25–11.5 inches in length and about 9–9.5 inches in width, though some listings show slightly different measurements such as 9.5 x 11.75 inches.
You’ll find internal prong fasteners (typically 3‑prong) built into some folders, and non‑pronged or translucent folders that are pre‑punched with a 3‑hole (3‑ring) punch for binder storage.
Most poly prong folders list two internal pockets, while clear binder sleeves typically provide a single pocket per sleeve.
Many pronged poly folders include three prongs to secure 3‑hole‑punched pages; some plastic folders are also described as pre‑punched with a 3‑ring hole so they can be stored in binders.
Review summaries most often praise durability and longevity (described as sturdy and long‑lasting), and many reviewers note good overall build and strong value for money.
